I'm actually in a similar boat. I bought a gt-i7500l second hand so I could get my feet wet with rooting and use it as a media player. When I plug it into my computer (Windows 7 starter) it will show up for half a second under my computer then disappears. I tried the samsung software and it told me that the phone does not support file transfer, which I find hard to swallow. I called samsung and they told me the same. If anyone has a fix it would be greatly appreciated. I've done all the above steps as well, and formatted the phone twice.