I recently purchased an 8 GB micro SD card for my MyTouch 3G. I had some videos on the old card that I moved over to the card. I also converted some videos from .avi to .mp4 format. However, now, none of the videos I have on the new SD card is working. Is that a codec issue? Do I need to uninstall then reinstall the player I am using (however, even the default video app will not play them). The ones I transferred over from the old SD card worked fine. Any Ideas...thank you.