WordPress bug or theme bug?

I’m using wordpress 2.3 with K2 RC3 theme
Is this a bug or what?
I’m creating a new page with a ‘phpMyChat’ in the page text.
Note: phpMyChat without the quote.
when i saved the page i got redirected to my default domain. Meaning that it’s an invalid filename.
that only happened if i enter an invalid address in my domain.
example: http://domain.com/page.html
if the filename page.html is not in my domain it will be redirected to my default domain.
I spend a whole 7 hour figuring this out.
It’s just the word ‘phpMyChat’ that triggers it.