I'm having a somewhat similar problem, I also have a 160gb harddrive and am using x2 4981.06 bios. Everything worked fine at first, all the space is shown in the f drive and everything. But recently avalaunch has not been able to boot any applications or games, it just freezes on the "please wait while launching ____" screen. THe only things I've recently done are install a few games, the complex tools app, and a few skins. So i'm not sure whats causing my problem, evox boots all my apps/games fine.
But about ava not seeing your drive space, its probably not the bios, but it may be your avalaunch settings. I'd make sure u have the latest version of avalaunch as well, because for whatever reason if your running an old version it may have some issues with big harddrives. So if its not seeing your drive space than that would make sense with why its also freezing when it tries to load things off the harddrive.
hmmmm