I don’t know why but suddenly all my pages (not posts) were being redirected to the archives.php template… weird! I disabled every plugin and it still happened. I changed themes and it was all ok, so i changed back to GP and it was fixed!
I’m telling you those damn fairies are freaking me out!
If all of the GP plugins and theme were deactivated and it was still occurring, I’m guessing your WP installation may be corrupted, or your server might be behaving strangely with the permalinks/redirect rules.