searching over the web, you can see that a lot of users had problems while playing interlaced mpeg files with stereoplayer. with a few simple steps you can solve this problem!
1) download and install "k-lite codec pack" (if you already have it you don't need to uninstall and then reinstall it.
(k-l cp can be downloaded here:
http://www.pc-facile.com/download/codec ... codecpack/ )
2) open the k-lite configuration tool like shown in th epicture below, and set the decoder like in the image. (click on the image to enlarge)

3) restart,
4) open stereoplayer, select the visualization tipe according to your visualization mode, (most will have Nvidia stereo drivers), load the movie, and then go fullscreen. should be 3D now..

bye
sharky[/url]