7811 Vista 64 bit; IEEE 1394 port drops connection

I seem to have a problem with my IEEE 1394 port (firewire). I have an external 500 GB WD hard drive that I used to connect to my Inspiron XPS Gen 2 via firewire without any trouble. On the P-7811 FX when I try to connect it the hard drive works for a while and then seems to get stuck if I enter a large folder, try to transfer large files, or do something else that's going to require full use of the drive and connection for a while. The drive's access light freezes as lit, there's no audible file accessing going on, and Windows Explorer locks up and has trouble obeying a task manager kill command.

To me, this looks like a driver problem because the port itself seems to work. I'm running a clean install of Vista 64 bit. About the only thing that's not stock on this system is the video driver (which is currently Gateway's 176). All other drivers are from the original restore CD. The system is completely stable other than this firewire issue. I've been looking for a new driver because I'm presuming this is a chipset issue, but thus far I haven't found anything.

Does anyone know if there's a new chipset driver out there somewhere? Am I correct in my assumption that this is chipset driver-related, or could it be something else?

Keep in mind that ports adjacent to the firewire port are all working normally.

Thanks!