Something strange going on in latest Ubuntu 10.04: just upgraded to the 2.6.32-22 kernel and expected the four Parallels Tools modules to be automatically recompiled via DKMS, but /lib/modules/2.6.32-22.../updates/dkms/ only shows three of these modules -- prl_fs_freeze.ko is missing and is not loaded either. However, when I reinstall Parallels Tools, all four modules are present in /lib/modules/2.6.32-22.../extra and all four modules are loaded after a reboot. Strangely enough, the three modules in updates/dkms are also updated with the recompiled ones (same time stamp as the ones in extra/). Why is prl_fs_freeze.ko excluded from DKMS? What does it do, anyway?