I was looking for a new media player for my galaxy S and after searching downloaded realplayer and doubletwist from the app store earlier today to have a look. After a few hours the phone stopped recognising my SD storage, i.e. as if there wasn't a card in there and I thought that I was in real trouble. Tried the usual off, on, battery out, SD card out, back on, etc... nothing. Luckily my car charger acts like a PC connection and kicks off the MTP application screen which started flashing. Having experienced this before (the cause of which was long filenames) I deleted both apps, off and on and everything started working again. I've left the title to this post quite open as hopefully it will help others if they experience similar problems with other applications.