When I try to load http://dilbert.com/strips/comic/2008-08-16 with swfdec 0.7.4 and swfdec-mozilla 0.7.4, I get segmentation fault.
Using Firefox 3.0.1 on Arch Linux x86_64, kernel 2.6.26. Too tired to get a backtrace, so sorry if this isn't very helpful, but thought I'd report it anyway.
Please get a backtrace and search the bugzilla next time ;)
*** This bug has been marked as a duplicate of bug 16103 ***