We are sorry for the inconvenience that we caused to you.
With the official release of Q1 2010 we will publish a list with the changes that may break the themes.
We can also assist you with fixing your custom theme if you send it to us or make a new one for you if you provide us with the changes that you did.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.