Any reasons to recompile Silverlight 3 controls for Silverlight 4?

When I release a custom control which works in both Silverlight 3 and Silverlight 4 is there any reason to provide a separate binary version targeted at Silverlight 4?

As far as I understand SL4 apps using SL3 controls run normally in SL4 mode but maybe there are some hidden benefits of recompil开发者_StackOverflow中文版ing controls for SL4 (or gotchas of not doing so).

No need to rebuild: the "quirks mode" actually is based on the version that the application's built against, not its components.

Be warned that if there is a breaking change in the XAML that would affect your Silverlight 3 control when it moves to Silverlight 4, even if you don't rebuild the control, if it's used in a v4.0 app it could throw an exception at runtime.