Losing Editor Changes on Package or SVN import/export

I have the folowing (Unity 3.5 Pro) problem:

When i create a package or import/export via SVN, cases where the Libary folder looses its relevance, i loose also my editor changes especially material changes like color or mapping. It seems like prefabs are reimported with thier original colors/mapping.

For SVN purposes i've forced Text Asset Serialization and Meta Files, though that shouldnt matter with packages.

Did anyone encounter this problem too and might found a solution?