A likely candidate for this could be the powersave scripts. Can you please uninstall the pm-utils-powersave-policy package, and check if it still happens?
If so, please reinstall it again, and try this instead:
sudo mv /usr/lib/pm-utils/power.d/95hdparm-apm /usr/lib/pm-utils/power.d/95hdparm-apm.orig
If it still happens, please move it back with
sudo mv /usr/lib/pm-utils/power.d/95hdparm-apm.orig /usr/lib/pm-utils/power.d/95hdparm-apm
Right after you encounter such a freeze, can you please reboot and attach /var/log/kern.log?
A likely candidate for this could be the powersave scripts. Can you please uninstall the pm-utils- powersave- policy package, and check if it still happens?
If so, please reinstall it again, and try this instead:
sudo mv /usr/lib/ pm-utils/ power.d/ 95hdparm- apm /usr/lib/ pm-utils/ power.d/ 95hdparm- apm.orig
If it still happens, please move it back with
sudo mv /usr/lib/ pm-utils/ power.d/ 95hdparm- apm.orig /usr/lib/ pm-utils/ power.d/ 95hdparm- apm
Right after you encounter such a freeze, can you please reboot and attach /var/log/kern.log?