We've made a "slight" change to how the personal top channels listing works on the Channels tab. Until now it has displayed the top channels by the total number of votes you have cast for a channel. Now it displays them by the highest number of votes you have received for any of your videos in that channel.

The listing isn't that significant to the community, afaik, and the reason for the change is so that in v3.3 we will be able to maintain a channel top users listing (like the current top user sidebars except for each specific channel).