Error: Callout mechanism not available

Hi.  When trying to open the Demo master, I receive this error after a few moments.

When trying the Simple Demo master, I get the error in SqueakDebug1.log.

I'm running a GeForce 7800GT, have OpenAL installed, just updated the nVidia drivers, and have shut down all non-essential tasks.

It appears to be an OpenGL related error...any thoughts on how to correct it?