Hi again, The problem seems to have gone away when I upgraded to a newer kernel: inux-image-2.6.29-1-686 2.6.29-2 inux-image-2.6.29-1-686 2.6.29-3(two different machines, varying mixes of stable and testing+unstable packages).
I don't know any more as to the cause of the problem, but I haven't seen any freezes occur since upgrading to the 2.6.29 kernels.
Jan Punt