Was having problems with the Sansa Fuze 4G port dropping out on my USB connection so here are some things that I did that seems to have fixed everything.
1st, I reinstalled WinAmp telling it to NOT install it’s portable media driver setup.
2nd, I reinstalled the recent version 11 of Windows Media Player.
3rd, I installed the Media Transfer Kit that I downloaded from Microsoft (mtppk12.exe).
4th, I installed a Hotfix also downloaded from Microsoft (windowsmedia11-kb935552-x86-intl.exe) (Win XP only)
5th, I switched the 4G player to a different USB port.
The mtppk12.exe was just a generic loader program that loaded 2 USB drivers.
The Hotfix cured some problems I was having with cross-talk beteween USB ports. This cross-talk caused some problems with my portable hard drive that required “chkdsk /f” to fix. Basically, I was not able to use the Sansa Fuze 4G port at the same time I was using the portable hard drive. No problems there now.
Hope this helps someone else.