Question : Problem: Computer recognizing one but not two other firewire devices

My computer (homebuilt) is failing to recognize a couple of firewire devices Id like to hook up to it. They are:

1.      Tascam FW1884 (basically, a mixing board)
2.      Canon HV20 video camera

The 1884 is a recent purchase (i.e. one week ago) and has never been recognized by the computer. As for the HV20, Ive had it for eight months. At first, Adobe Premier Pro 2.0 (PP2) didnt pick it up, but eventually it did, and I was able to grab video off the HV20 for approximately three months, though Im not sure what made the difference. During this time, I never looked in the device manager to see if the HV20 was listed there; however, the computer made the familiar bing sound whenever the camera was turned on or off. At the time of this writing (April 2, 2008), the computer doesnt recognize either device, and the HV20 is no longer recognized by PP2.

I have four firewire ports. One is integrated into the motherboard, and has NEVER picked up either device. The remaining three ports are on a PCI card, and none of them now pick up either device. However, when the computer did recognize the HV20, it was through one of the ports on this PCI card.

The integrated firewire port does work with a third firewire device I have, an external HDD, so I know this port is not broken. The three firewire ports of the PCI card also pick up the HDD, meaning that when the HDD is plugged into any of these ports, it appears in Device Manager. However, When the HDD is plugged into the first firewire port on the PCI card, it works for a few minutes, and Im able to browse it, but then it disappears from Device Manager. When its plugged into the second and third firewire port on the PCI card, it appears in Device Manager, but the volume is unreadable according to the populate button.

The cable Ive used to plug in the HDD is the cable that came with the 1884 (6-pin to 6-pin), so I know that cable works. As for the cable that came with the HV20 (4-pin to 6-pin), since it did work at one point, I assume it also is a healthy cable.

Knowing this background, how can I resolve the problem of my computer not detecting either the 1884 or the HV20?

Thank you very much for your help.

System Information:

Microsoft Windows XP Professional x64 Edition
Version 5.2.3790, Service Pack 2, Build 3790

ASUS M2N32-SLI DELUXE Motherboard ACPI
BIOS Revision 1802, 31-Jan-08
Memory: 2,046.31 MB
AMD Athlon 64 Processor 3800+

Answer : Problem: Computer recognizing one but not two other firewire devices

i would start by testing the devices on another PC; one or bath can be bad.