it doesnt work it just freezes the image.

Been e-mailing with Todd from tech support on this issue.
He's puzzled, apparently that's not supposed to happen.
He's going to bring up the issue with the engineers tomorrow.

cool thank you!

Ok here's Todd's answer:

The behavior you are seeing with the 3D selection mode is perfectly normal, it turns out. I brought this up at our meeting today, and the use of that configuration mode was made more clear to me. The VR920 will automatically detect all dominance in field sequential 3D, and switch to the appropriate mode with no need for manual configuration. In older versions of the nVidia stereo drivers, sometimes the proper signal would be sent, requiring the use of the button to switch modes if the image seemed distorted. This legacy use is almost never needed at this point. It was kept in the VR920's OSD, though, because on occasion, the signal to go back to mono mode is lost, and you get stuck in 3D mode. This allows you to go back to mono.

If you're interested in the details behind the behavior you're seeing, it's rather simple, it turns out. The switching between left eye field and right eye field is accomplished via a signal which comes through the USB connection. When you are manually taking the VR920 to 3D mode, using that button, you are seeing the last frame of the video that had been playing, typically your desktop. That single frame is sitting in the displays, because the USB has cleared the frame buffer, and is waiting for the signal to send the next frame along. Since there is no signal (the computer is 2D mode, after all, so no switching is actually occurring), the last frame just sits there. When you switch back to 2D mode, the video again starts playing at 60 frames per second.

Also, as to the stereo jpeg viewer, we are definitely working on a releasable version of one. I would expect it to be up on our website in the next couple of weeks. It will be part of new versions of our software, and we are also discussing making it a stand-alone download.

cool what about software page flip?

If a program talks about software page filp, you will need to read the program's instructions to find out what it really means.

If they mean the software is just rendering the left frame then just rendering the right frame, without telling anything which frame it is currently up to, but trying to keep it synced with the vertical retraces, then the bad news is... Vuzix disabled that feature in the firmware update, perhaps by accident, perhaps by miscommunication, or perhaps deliberately.

The good news is that once they release the SDK, I (or anyone else) can make a simple program that runs in the background and uses a timer to tell the glasses to switch eyes at 60Hz. Or I could make a program that hooks into the Direct3D present function so that it switches eyes every software frame, which would work more reliably.

Todd's comments aren't entirely clear, but I think what he is saying is this:

When using the nvidia stereo drivers, the graphics card sends a signal on one of the VGA pins to say which eye that frame is for, and the VR920 goes into nvidia stereo driver mode and strictly obeys the eye specified on that pin. So there is no need to manually swap which eye is which using the menu when in nvidia stereo driver mode. But you can still manually switch out of nvidia stereo driver mode if for some reason it doesn't do so automatically.

When using software that natively supports the VR920, it will only switch which eye the current frame goes to when told to via a USB command, and it will only display a frame once per eye switch. So if a program says "OK now do the left eye" and sends a frame to display, the VR920 will think "I didn't already have the left eye image, so I'm going to display this frame on the left screen." Then when the program sends another frame the VR920 will think "I've already got the left frame, so I'm just going to ignore this new frame." Then if the program says "OK now do the right eye", and sends a frame, the VR920 will think "I didn't already have the right eye image, so I'm going to display this frame on the right screen". Then if the program says "OK now do the left eye" and sends a frame to display, the VR920 will think "I didn't already have the left eye image, so I'm going to display this frame on the left screen.". There is therefore also no need to swap which eye is which manually in this mode. Although you might need to manually switch out of this mode if the program crashes before it sends a USB command to stop displaying stereo.

There used to be a third stereo mode which would just switch eyes once per frame and you could choose it from the menu. It would assume the first frame was for the left eye, then the next frame was for the right eye, then the next frame was the the left eye, etc. But sometimes it would get it backwards, and you would need to be able to specify that the first frame was for the right eye, the second for the left eye, and the third for the right eye, etc. So you needed to be able to manually choose L first or R first in the VR920's menu. But Vuzix stuffed up this mode by basically assuming it was the same as the stereo mode for native VR920 software.

Hopefully the third mode will be available again in the firmware update after the current one. But I wouldn't expect it in Release Candidate 2.

How can it be done? How can an application change the behaviour of another direct3d application? I'm very interested in knowing where can I find information about that kind of things.
Is it related to the stereo drivers you are working on?

I use MadCodeHooks whenever I want to hook into other people's Direct3D or OpenGL functions. It comes with a sample that makes all games render in wireframe, unless they want to render in wireframe in which case they render solid.
Like all good things, MadCodeHooks is written in Borland Delphi (pascal). But you can still use it from C if you haven't learnt to appreciate the wonders of pascal.

Great I learned a little delphi (and pascal). Is it open source, so you can see the code (and change it a little)?

Maybe it'd be possible to make 2 Frames out of one... who knows
Do you have a link?
--> I'll search for one myself, when I've got more time

MadCodeHooks, which just does all kinds of hooking, isn't open source. You have to pay lots of money to buy the source. But you can use it for free yourself to play around with, and you can buy a non-commercial licence for a token price if you want to distribute non-commercial software made using it. It comes with a very simple sample code (without much comments) for hooking Direct3D to make it wireframe.

However hooking all of Direct3D (From 1 to 10) is a lot of work.

My code that I wrote for hooking all of Direct3D and doing head-tracked perspective hasn't been touched for ages, and it relies on being configured by editing the source code, and is full of bugs. I probably should stop messing around with DOSBOX and get a move on with working on it. But as my VR920 still has the old firmware and I'm too scared to update it, and Vuzix haven't released their stereo SDK yet, I could only implement anaglyph at the moment.