certain word combinations result in 403 forbidden errors

I don’t know what might be causing this. I am completely dumbfounded.

I am trying to create a ‘draft’ post. Subject is ‘test.’ If the body of the post contains a certain string, then an attempt to save it gives me a 403 forbidden error. If I avoid that string, it will work fine.

The text of my original post was much longer, but through extensive trial and error I was able to reduce it down to:

Lynx (a

will give me a 403 forbidden error, while

Lynx, (a

does not. This simple addition of a comma solved the problem.

Can somebody else test this? This has got to be one of the strangest errors I have ever seen.