Search Error When Using Apostrophes

[s²]

A member of my forum reported this error:

For some reason the search does not recognize apostrophes as part of regular speech - the results that I get when trying to search for a phrase that includes an apostrophe ends with me getting the message:

Forbidden
You don't have permission to access /index.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

I get by with using alternate terms, but I thought you might want to know. Is this a common occurence or related to me specifically? At the moment I'm on Redhat 9, Firefox 2.

In relation, the error log had this: (asterisks for privacy)

http://****/index.php?action=search2
8: Undefined index: brd
File: /home/****/public_html/Sources/Search.php
Line: 407

I went ahead and looked up the error on the forum, and came across this fix.  I applied it, and asked the member to try again.  They got the same error.  Even I tried it by throwing in an apostrophe and got the same result.

Using SMF 1.1.3 with the following mods:
1.     Integrated Chat      2.7      
2.    TinyPortal    0.983
3.    Users Online Today Mod    1.4.0    
4.    Default Membergroup on Registration    1.0    
5.    Merge Double Posts    1.0.8
6.    SMF Gallery Lite

[jerm]

Have you tried to replace Search.php with a fresh copy.

[s²]

Yes, I get the same error as before.

[SleePy]

This was a bug in 1.1.3 or 1.1.2 (I forget which) But it was fixed.
Are you sure you replace the file?
Some FTP clients have issues with replacing files so try deleting the search file then upload it.

What theme are you using?

[Ben_S]

Sounds like mod_security

Having problems with mod_security?

[s²]

I am using the default theme, and I made sure that the change happened when I switched files to fix the bug.  I downloaded the file and the change was there.

This mod_security sounds familiar, because I am also having problems with the inline edit feature with the same error.  I will look into it and will try to report back.  Thank you for your help.

EDIT: It was mod_security.  Applied the fix, and now everything works.