That should not be happening. I have a Sony Cybershot DSC-W85 and have no problems whatsoever. This makes me think it is either a hardware problem (USB chipset/processor) or a corrupt OS. The first thing you want to do is put in your install disk 1 (the Apple dvd) and reboot into install mode. When it starts up DO NOT reinstall OS X. Just open Disk Utility and click on your boot drive. Then, press Repair disk, then Repair Disk permissions. Be prepared to wait. Then restart and try your camera.
If that does not work, back up ALL of your data to another computer or drive. We will archive it, but it may be necessary to lose it. AFTER backing up, boot back to install disk 1, then follow the directions to reinstall OS X, but make sure you choose Archive and Install, not Erase and Install. That may be under customize. When finished, reboot, install all updates, reboot as necessary, then plug in your camera. If it works, move your data back.
If that does not work, document what you have done, make a Genius Bar appointment and tell them exactly what is happening. I assume this camera works fine on other computers, so that should not be where the problem is coming from. If reinstalling OS X does not fix it, it must be a hardware problem.