I recently installed 11.10 on my new HP dm1z (using wubi). Most of the conversations about this machine have centered on the wireless drivers or the touchpad, but I can't find anyone (except for one blog post elsewhere) who talks about the random freezing effect.
About every other day, everything just freezes: the mouse, the programs, everything. Ctl-alt-del does nothing, so I eventually have to just turn the machine off by holding the power button. I can't find any consistent reason, as it seems to happen regardless of the number of programs open, what I'm doing, etc. (I can't remember if it happened when I was using a direct ethernet connection or if it's only when the wireless is activated.)
I know it's a longshot, but part of me wonders if it has anything to do with HP's CoolSense program, which in Windows uses some sort of (I assume?) hardware to know if the laptop is bumping around or sitting on a desk, adjusting fan power accordingly. The only reason I suggest that is because it froze once right after I moved it from my lap to the couch--a possible movement issue--and because CoolSense feels fancy enough that I know nothing about it.