[Plugin: Popularity Contest 1.3b3]

After upgrading to WordPress 2.5, my Popularity Contest 1.3b3 plugin generates a Fatal Error. I have tried activating only this plugin, and activating everything else and then Popularity Contest 1.3b3, and a couple of other variations. I had it working with 2.3.

Is anyone else getting this error or does the 2.5 engine react differently to something else to break PC 1.3b3?