My USB Devices seemingly disconnect at random intervals I have a Early 2008 24" iMac.  On my USB ports, I have my wired keyboard, my external Seagate HD (for Time Machine), and I have a joystick. For quite some time, it seems like all of my USB devices keep disconnecting, and then reconnecting. This is particularly bad when it comes to my backups.

What can I do to stop this behavior from happening, and what more do I need to provide to help with this very annoying.
Are there any USB hubs connected or the devices connected directly to the mac?  If there is a hub, consider disconnecting it and seeing if it helps.  If not, does the problem go away if you remove one of the devices? I have seen some weird issues with a device intermittently shorting out.