If you were trying to instal the RTM version of TE2010, then yes you would need to uninstall the RC of TFS 2010 and install the new one. The RTM versions are not compatible with the RC versions. If you get a chance, let us know if this resolves the issue.
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