Thanks for the comment. The only directly related thing I found (to which I am unable to contribute) was this
But that stated (wrongly according to my experience) in comment 4: Hibernate works again since kernel 3.2.5-3.fc16.i686 (or possibly one of the other packages that came in the upgrade). Closing this bug.
Unfortunately, I still get (intermittently) freezing during pm-hibernate after something like this is printed out:
[paraphrase] using 3 threads for compression.
PM: Compressing and saving image data nn%
Some times it freezes immediately. Sometimes the nn% pauses and changes a few times then freezes.
(My E6410 has a four core intel i5 cpu, with intel graphic card.)
Normally it doesn't freeze the first time I use pm-hibernate. It may work fine two or three times, then freeze on the next one. Memory 4G, swap area 10G.
When it works, hibernation and resume are very fast. My hunch is that the code for multi-threaded compression does not cover enough cases and still has bugs.
Unfortunately I am not a system programmer and cannot dig into kernel software to experiment.
Could this have anything to do with the fact that I run neither gnome nor kde. I boot into runlevel 3 )multi-user text only) then use startx to run X11 with CTWM (or sometimes OpenBox as window manager). Then I don't reboot until I have a special reason e.g. new kernel, because hibernate/resume keeps my 10 virtual desktops running. I have tried several versions of the 3.2 kernel. Each works for a while, then freezes. But 3.1.7-1 works perfectly, though more slowly.
If I can do any specific tests or provide more information about my configuration I am willing to try, though I'll be going away tomorrow to give a talk.