This is a bug with with the wp code.
http://trac.ww.wp.xz.cn/ticket/1614
The solution is an easy fix, you simply have to split up the line of code mentioned in the link and add in a temp variable (they use $crom) that takes the value $this->get(‘cat’)
The original code works in PHP4, but apparently not PHP5. I spent the better part of friday chasing that down.
