Firewire connectivity issues on Windows

[kgLum]

I'm trying to hook up a Sony vidcam thru Firewire/IEEE 1394. It doesn't work on two computers.
I've never used any of the involved components before so I don't know what to blame, and I don't have other gear to test with.
I thought maybe someone's had experience with similar problems.

Camera side: I switch it to VCR mode. With a hooked cable the cam screen shows "DV IN" (or something similar), so it at least detects the connection on some level.

Computer A: PCIe 1394 card, WinXP. Connecting the vidcam, no camera device is detected by Windows. Nothing appears in Device Manager.

Computer B: onboard 1394, WinXP. Connecting the vidcam Windows detects it (on first hookup I saw the camera model flashing briefly in Device Manager, before the cam drivers installed). It then tries to auto-install the generic camera drivers. The driver install freezes in most cases, though the rest of Windows remains responsive. If I turn off the camera it unfreezes. After playing with it some - restarts, camera off/on, etc. - I finally had a seemingly successfully installed and detected Sony camera driver under Imaging Devices.

Behavior on computer B: Despite a camera device appearing in Device Manager, two DV capture apps (WinDV & DVapp) don't see the camera. WinDV just sees a USB webcam connected to the computer, and DVapp finds nothings. And if I turn the camera off and on again, sometimes it's no longer detected even by Windows.

I get the same behavior, on both computers, also when using 1394 drivers from WinXP pre-SP1, which apparently helped many people solve issues.

Now, I don't know if any of the components are okay: camera, 1394 cable, PCIe 1394 card, onboard 1394.
What's strange and I can't explain is the difference in behavior between the computers, despite both using a similiar VIA 1394 chip of the same series.

Any ideas?

[october262]

Go into the device manager and try updating the drivers for the
Firewire ports.

[jagabo]

Try a Firewire card based on the Texas Instruments chip. They cost more but they work with camcorders.

[kgLum]

I tried both Windows SP3's Firewire drivers and pre-SP1, both the variant that says VIA something (there are two of them actually) and the one that just says OHCI complaint.
There are no drivers directly from VIA as far as I know, because Firewire drivers have been included with Windows since Win98.

Are there known compatibility problems between VIA 6307/6308 and certain cameras?
User reviews here suggest 6307 works fine with various Sony cams.