Same problem in my Sony Vaio Z1RMP (ati mobility RV100 or RV200 - i don't remember).
I use the open source driver "ati" in my xorg.conf file.
I use the lasted kernel (2.6.15-26-686 #1 SMP PREEMPT)
When i switch GTK application to an another GTK application my system freeze (3 time today, but 0 time last week).
I use a laptop (today witch AC Sector) and all works properly.
My system is an upgrade from debian sarge -> hoary -> breezy -> dapper.
Same problem in my Sony Vaio Z1RMP (ati mobility RV100 or RV200 - i don't remember).
I use the open source driver "ati" in my xorg.conf file.
I use the lasted kernel (2.6.15-26-686 #1 SMP PREEMPT)
When i switch GTK application to an another GTK application my system freeze (3 time today, but 0 time last week).
I use a laptop (today witch AC Sector) and all works properly.
My system is an upgrade from debian sarge -> hoary -> breezy -> dapper.