Bug#886858:

[Dennis Heddicke]

The bug is fixed for me with the last kernel update (3.16.0-6-686-pae). 
I don't know if it was a real bug or a side effect of a mixture of 
packages from stable and unstable (among other things libc6). Last week 
i reverted all packages to stable. Maybe this solved the issue. Thank 
you for your help.