This could be the common problem with cubase and the P4 CPU.

This link should tell you everything you need to know, if de-normal mode is indeed the problem.

http://www.soundonsound.com/sos/oct02/articles/pcnotes1002.asp[/url]

Good Luck ;)

Edit: The above link is playing up but so the second link below is a link to the google search engine (if that doesn't work there is info on the denormal mode everywhere including here (http://www.tobybear.de/p_utilbag.html)

http://www.google.com.au/search?as_q...mp;safe=images