So I've been banging my head against the wall on this since tuesday. I can use iz3d in side by side mode and that works okay, but there are games where I'm not happy with performance at 1080p side by side, and feel that properly output 720p 3D would fix this. I have a PS3 and I have confirmed that using the same HDMI cable I use on my PC works there for 3D output. I've tried setting my desktop resolution to the appropriate HZ and resolutions for both 720 60hz and 1080 24hz and nothing has worked. I tried Tridef, and got the same results.

When I try the static test in iz3d (or try to start a game), the screen goes black with a flashing mouse cursor and stays that way until I hit escape enough times. My graphics card and TV are both listed as compatible on ATi's HD3D site, so I'm really confused at this point. It's not a huge deal not to have the TV automatically switch over to 3D, but I feel like I'm throwing away frames in side by side mode. I hope someone here knows enough to help me get to the bottom of all this!

Could you try setting a 1280x1470 graphics mode at 60Hz with your TV connected to your PC ?

Could you please list the rest of your PCs specs and relevant driver versions (most importantly the OS and whether its 32 or 64-bit, the AMD driver number and the iz3D / DDD driver numbers). If you run the DDD AMD checker, do you pass? Are you running Crossfire or anything weird? Are you running dual monitors? Sometimes you might have to have the TV as your sole output (primary display with no secondary monitor). Did you try switching which HDMI port it was plugged into on the back of the TV (sometimes only 1 works for 3D). Though I have neither an AMD card nor a 3D HDTV, so I can't really help you further.

plagiarize, are you by any chance using a receiver, or are you connecting the PC to the TV directly?
If you are using a receiver I suggest connecting directly and if it works then you have to contact AMD to fix the problem.
I have a 5770 and experienced this exact problem. Before doing anything else it's a good idea to update to the latest catalyst version if you haven't, also switch off all other displays (like Cyber said). You have to have only the compatible display receiving signal, otherwise the tv is probably not getting recognized properly. Also setting the desktop resolution to 1080p@24 or 720p@60 is not a requirement, but setting the in-game resolution is.