My system doesn't freeze, but I do get low frame rates and stall warning buzzers and machine gun fire that won't stop. In other words, I'll almost stall, get the buzzer, correct it and start flying level or whatever. But no matter what I do, the stall buzzer continues, sounding sort of like an echo.
The same thing happens with machine guns.
It's only an occassional problem _ maybe once a week. It usually goes away if I quit and then relog. I always put it down to my system barely meeting the AH requirements, but maybe it isn't.
My system
AMD 400
64 megs ram
SB 16
Voodoo III 16