I have a WD My Passport Essential (Model number WD 2500ME/2500BEV) connected to a USB 2.0 front connector in an old Emachines box. Occasionally (thus far only observed in Windows XP) the drive will randomly disconnect with the general Windows dings, pause for a few seconds, then reconnect. This seems to occur when the drive is not in active use, although I'm not sure if an active portable program thats in the background quality as active use.
At first I thought this was overheating, but the drive itself is not hot, just a little warm. And even then its pretty close to a floor AC vent and sitting on top of the case. The drive nor its cable isn't touched before the disconnect, so that rules out accidental jostling. Nothing software wise should be affecting it. As I said earlier I've only noticed it in Windows XP, but that could simply be because I don't use Linux as my primary OS right now. The drive itself runs fine with no weird noises or system crashes.
With all the above, what could cause an issue like this? I'm really at a loss here and its getting annoying when I'm running a portable app and it crashes because the drive got disconnected.