I've uninstalled the apple drivers and reinstalled itune as well. I also reset my IRQ's to auto in the bios with no change in the issue. I reset my bios by turning off and pulling the battery from the motherboard. This is quite the pain, as you can imagine because I can't just plug my iphone in to charge while I'm using the usb drive. If the iphone is plugged in first and then I plug the drive in it says 'unknown usb device' and wont mount the hard drive and fails to install drivers that work fine without the iphone plugged in.

I found that if I unplugged my iphone from the computer and replugged in the Seagate drive all the files would show up again and have all the data they were supposed to have (ie video files would not just say their size, but would also play their content.) When I plug my iphone into my computer I find that my USB drive stops being active - the files and folders all still show up but all the files are 'hollow' and missing any data they once retained (files show up but wont open)

Iphone 4s usb driver download