Installing 3rd card PCIe went wrong... noise

[Inthebox]

Hi there

Ordered an Pcie Accel card from the States, so I could upgrade from my current PT8 HD2 to HD3 setup.

After installing the card with flex in the slot 0 (core in slot 2 and first accel in slot 1) I rebooted my mac pro and ran the Digitest on all three cards. All cards passed the test.

When opening the session I am working on, noise started to emerge during the last stages of opening the session. When the session opened, white noise is coming from approx. 1/3 of the tracks + master (of course)

Making plugins inactive on the noisy tracks makes noise disappear.

Some tracks distorting during playback.

Tried quitting Pro Tools and running trash prefs app, rebooted but same problem. Tried making new session and session-importing all tracks from the old, but same problem.

Finally removed 3rd card, and everything is back to normal HD2, and working fine.

Did I buy a bad card, or am I missing something?

Cheers

Lars

Mac Pro intel XEON 1.1
Mac OS 10.6.8
Pro Tools HD 8.1.1.1
192 I/0