I can confirm this problem using Edgy (64bit, gnome) and nvidia-glx.
I can also confirm that disabling the the work-around suggested by jamespharaoh (disabling the composite extension) does work.
I'm going to see if I can get the latest nvidia-glx drivers installed manually - if that solves the problem (without disabling the composite extension), I will report it here.
I can confirm this problem using Edgy (64bit, gnome) and nvidia-glx.
I can also confirm that disabling the the work-around suggested by jamespharaoh (disabling the composite extension) does work.
I'm going to see if I can get the latest nvidia-glx drivers installed manually - if that solves the problem (without disabling the composite extension), I will report it here.