Very strange posting error

[Hawkes]

I have SMF 1.1rc2 still and was copying a post from another website to mine.  While the post itself is quite long I was able to narrow down the problem in the post to a certain section.  For some reason when I kept this in the post, I would get a Forbidden Access error.  I had to actually modify the original content for the post to go through.  This would happen in either preview mode or straight post without a preview.

The specific area of the post that tripped the error:

NC<space right after NC>

I had to change this to:

NC.

It didn't do it with NC by itself, just NC followed by a space.  It doesn't do it here, so I assume it was corrected in 1.1rc3.  I haven't upgraded to rc3 yet, so I thought I'd post this for those still running rc2 or in case it creeps up again.

[Oldiesmann]

Sounds like mod_security. Try Having problems with mod_security? and see if that fixes the issue.