I also seem to have randomly occuring freezes of totalmix fx in windows 7.
I first found it happening when i went from sonar x3 to mediamonkey, then after closing media monkey, TotalMixFX.exe *32 would start hogging CPU up to about 60%, and then slow everything down to a crawl.
After suspecting a conflict with media monkey, I then noticed a similar problem using windows media player, and just recently after I opened Firefox to check something on the internet.
I cannot really locate the reason for the intermittent problem. I suspect there is another program in Windows or some other hardware issue which is conflicting in some way, but I don't know what.
I can stop the problem by going to Fireface USB settings, then select anything and click OK. The CPU load then decreases to about 1 or 2% immediately.
It hasn't occured during recording yet, but it worries me a little.
I run Babyface with Windows 7 Ultimate, 64 bit, and Sonar x3 in 32 bit mode, and record mostly in 24bit/48k Hz. I also have Behringer ADA8000 hooked up for ADAT i/o, with clocking to Babyface internal.
Computer is Core2Duo E6550 CPU on G41MCOMBO motherboard, with 4GB RAM.
Glad for any suggestions.
Jon.