Ummm...lots...
OS, software, audio card, memory etc etc...
What are you recording? Analog or digital..
Sounds to me like it's possibly a clocking issue if you are getting random white noise bursts..
tell us your audio setup...
Opus

thanks for the reply!!!!
Here is the rig!!!
am athalon xp2000+ on am MSI K7T266 pro w/ 512megs of DDR ramm, adaptec scsi controller card for the 36 gig 10000 rpm drive, Hammerfall 52/96, matrox g450 video card, windows 98se, one fourty gig maxtor 7200 drive for apps, one ibm 80gig drive for video editing, plextor cd burner. Using nuendo 1.5.2 with the hammerfall as the master wordclock to my spirit 328 recording board, a digimax presonus for an aditional 8 ins. from the board to the computer via adat light pipe. all of the viruatl memory is disengaed and the only draw back there is that I can't burn cd's from that setting. the hammerfall is set to maximum latency (8000) something or other??? and i monitor straight off of the spirit board through my mackie HR824's

First of all dont disable the virtual memory...it is highly NOT reccomended that you do that to your system...Every major computer geek site/forums I have come across have always said not to do that...I would definately take their word for it!
So you have the 9652 card as the word clock master and the Spirit board slaving to it...Optical out of the DigiMax into the Spirit then into the Hammerfall...What is the setting for the DigiMax? Is that set to master? If so then that could be your answer..You want ONE piece to be the master and only ONE..(Highlander quote....There can only be ONE!!! lol)
What you should do is have the Hammerfall be the slave and send word clock out from the DigiMax into the Spirit board with a BNC T split..take the split from there into the Hammerfall card..this way using the split will reduce throughput time on the word clock chain taking away any possible lag time on the clock.
Also why do you have the 9652 card set to 8000 buffer size? That's a hell of a load and latency will be way too high at that point..unless you dont need to direct monitor..
Or what you could do is have the Spirit board clock to the Optical and then have the 9652 card clock to the optical ins as well...
Opus

I coudl care less about the latency issue due to the fact that i monitor from the spirit 328 not from the computer. the only thing about that is I can use any of the nuendo or plugin bundles in real time while i record. oh well. But as to the virtual memory if I even have it set to a 2-3 ratio of what i really have in there then the drag in performance is unbelievable. it responds terribly and has all kinds of lag between button or mouse klicks. with out the virtual ram engaged the system just rules on the fly and response time. I will check the digimax as I son't even have it BNC'ed up to the hammerfall.