Hi Tim!
It seems that eAccelerator under FreeBSD has the same Bugs as the Windows version. Version 0.9.5 crashes if protected functions are used. See ticket #231 on the eAccelerator bugtracker. Sorry for not pointing to this earlier, but I never heard that this occurred on a system running a non-windows OS.
I tried to recompile eAccelerator after all of the other updates were complete and that mad no difference.
The latest snapshot shall have a fix for it, but I haven't tried yet.
It appears that there is some issue with mediawiki, php v5.2.0, and eAccelerator v.0.9.5. Seeing that none of my other php applications are having an issue I am guessing that there is a bug somewhere in mediawiki's script that checks to see if you are logged in or not.
JpGraph kills eAccelerator too. Theres no bug in MediaWiki but in eAccelerator.
After out many different ideas my workaround ended up being to add the following in my .htaccess file in my mediawiki directory;
php_value eaccelerator.filter "*.php !/data/webapps/mediawiki-1.8.2/includes/*.php"
Disabling it completely works too: ;-)
php_value eaccelerator.enable "0"
Maybe it helps even it's a little late.
Stefan