I've been trying to get LimitCats v1.1. to work for a while now, and I've had no luck. I looked for a new version on the main page of his RedAlt.com site, and didn't see one (the "WordPress downloads" page just lists v1.1. However, I made one last attempt to find a new version (because I really liked the plugin when it worked with my previous WP versions), so I typed "limitcats," "owen winkler" and "redalt.com" into Google, and I found a page at RedAlt with some persons asking about WP 2.0, and Owen suggested downloading the latest version, 1.5, with a link to it:
So, if v1.1 isn't working for you, try this new version.