base-3.0.3.0 not backwards compatible with base-3.0.2.0

[Stefan Holdermans]

Hi all,

Could anyone confirm the following claims?

* base-3.0.3.0 (shipped with GHC 6.10.1) is supposed to be backwards  
compatible with base-3.0.2.0 (shipped with GHC 6.8.3) ...

* ... but it isn't! (For example, the Arrow class from Control.Arrow  
is a subclass of Category from Control.Category in base-3.0.3.0, but  
not in base-3.0.2.0.)

Do we know of any similar issues? What's the recommended workaround  
when shipping code that is to support both GHC 6.8.* and GHC 6.10.*?)

Thanks,

   Stefan