Unable To Delete, Error Message Occurring

[Memphis834@yaho]

When I try and mark a post for deletion then click delete posts, I keep getting this message:

Not Found

The requested URL /inlinemod.php was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

[Dismounted]

It seems that you have not uploaded the inlinemod.php file. Make sure you've uploaded it.

[Marco van Herwaarden]

This may be due to mod_security.
While mod_security can be a very powerful tool, misconfigured or overly strict rule sets can interfere with vBulletins Operation. Below for Apache users you can use an htaccess file and add a specific rule to disable mod_security.
Make or edit your forum .htaccess file and add the following code
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>
Note, place this file in your main forum directory.
See this also thread: http://www.vbulletin.com/forum/showthread.php?t=167121

If this is not the solution to your problem, you might also be running Suhosin/Hardened PHP, see you PHP-Info to check if this is installed.