external firewire drive and firewire audio device

Using an external firewire drive while using my firepod or phonic mixer makes jack stop. Any ideas on how to get the two working together? I tried this on my laptop, dell latitude d505, using a TI chipset firewire card for the firepod and the built in firewire for the drive, didn't work on my ibm laptop either, but using both ports on the TI card. I haven't tried it on my rackmount PC yet. Any ideas as to what I should check? Using a usb drive is not necessarily a problem, but I want to know everything is working and firewire is better for audio drives than USB, though for my limited track count needs it doesn't make too much difference. Thanks.