I had a similar problem since my home directory was read only and some flash objects were trying to install a shared object in the ~/.macromedia directory. Changing ~ to rw or linking .macromedia to /tmp solves the problem.

Nope, it's on my linux partition. rw - I will check, but I don't think it has to do with flash actually. I will try it out on some webpages.

Tried it on a page with absolutely no flash. It crashes when I reload the page.

I don't experience crashes anymore. Don't know what makes the difference but I converted from xfree to xorg and also reinstalled the nvidia driver and removed the debian nvidia packages.

Upgraded to firefox Debian package 1.0.6-2. It's working just fine!
E

Just by removing directory .macromedia solved it on my machine (Debian unstable).

This development is rather interesting, since I've been convincing myself I am the only one with this problem 8) . I'm running Kanotix, which is actually Sid, with Debian k7 kernel and xorg, everything JustWorked up to couple of days ago when I apt-got ffox 1.06-3, and oh mighty crashing commenced. I installed Opera 8.02, and it worked, but instead of flash animations all I got were black squares, so I figured the fox problem is all about flash... and when I removed it everything (firefox) worked again. Wierd, I will try the remedy with .macromedia dir removal....

Damn it, I found out what caused flash to misbehave - I had composite extension loaded with X... not that I was running xcompmgr and transset actually, I simply had
Option "Composite" "Enable"
in my xorg.conf. Problem solved, at least for me...