I have a 5005-S507, and I experiece the same problems, however, I've been using linux on it for Almost a year and a half (since it came onto the market), so I've been able to find out some info on why it happens.
As near as I can tell, OSS, ALSA, ARTS, no matter what you end up using your gonna get some freezeups on wine and winex. When I try to trace it down it seems to lead to the ACPI settings of the sound card. Since the Toshiba soundcards on the higher models support acpi events, they are kind of buggy when they are in linux.
So, basically. Alsa wont help you much.
Kernel 2.6 might help both of us. I added you to my AOL account, using the info in your profile and will try helping you live when I see ya come on.