Gualty,
There have been no previous reports of this with the 1407 and 98, but I have a case reported with a 1408 and 95 where a third party pnp Sound Card was causing random crashes. Once the sound card was removed, it worked ok. I would not say that this is for sure the problem. The first step I would take is to make sure you have the latest version of IMAQ installed 2.5.3:
http://digital.ni.com/softlib.nsf/display?ReadForm&lookup=NI-IMAQ&view=current&node=132060_US
I hope this helps!
Chris D