With Q3.2009 we have introduced an improved rendering that solves a number of previous issues reported by our customers. Unfortunately this changes might cause some of the custom CSS that worked with the previous version to not work with the latest version.
To set a custom font to the dock's title use the .RadDock .rdCenter EM
class. For example the following CSS will make the title text bold:
.RadDock .rdCenter EM
the Telerik team