I don't think that setting you mention has anything to do with it.
/var/log/pm-suspend.log and see if it gives any hint.
These problems are usually due to some process(es) stopping the system from being suspended.
dmesg -T|grep Freez -A4
and look for these entries:
[sun mar 3 15:19:48 2013] Freezing user space processes ...
[sun mar 3 15:20:08 2013] Freezing of tasks failed after 20.01 seconds (3 tasks refusing to freeze, wq_busy=0):
[sun mar 3 15:20:08 2013] mount.nfs D e8631aa0 0 5518 5517 0x00800004
[sun mar 3 15:20:08 2013] e8631b10 00000086 f7bc0e00 e8631aa0 c1053cb4 c1809020 c192ee00 c192ee00
Check the time stamps to see which of the reported problems relate to your try to suspend. In this case, it is
mount.nfs that is causeing the problems.
Now, put a script in
/etc/pm/sleep.d/, scripts there will be run at suspend and resume. The file name should start with an ordering number, 00-49 for user scripts (for more details, see
The script could look like this
(killall -9 mount.nfs; exit 0)
with correpsonding entries for other processes that caused problems, if any.
exit 0 is a trick: if the process isn't found,
killall will exit with exit code 1, which will cancel the entire suspend. The above will run
killall in a sub-shell that will exit with 0.
If you're having problems, check
/var/log/pm-suspend.log that will log the attempt to suspend and to run your script.