Hello,
we have a problem with eAccelerator 0.9.5-rc1 on PHP 4.4.4, compiled and used on a Debian X86 box. phpinfo() can be found on http://schreinerei-nau.de/phpinfo.php
We had disabled safe_mode on a per-virtualhost basis for using the shell_exec function. The phpinfo() output had reflect the change: safe_mode was Off in the "Local" column, but PHP still claimed about it can't use shell_exec() with safe_mode enabled:
Warning: shell_exec(): Cannot execute using backquotes in Safe Mode in
**********.php on line 10
Without eAccelerator the problem was gone, so it seems to be a bug in eAccelerator rather then PHP.