Multilanguage Setup. I Just can't save the Language in Product.

[Criz]

Hi, first of all i'd like to thank for all the answers i had already found in this forum.
I use:
Joomla 2.5
VM 2.0

My problem: I have a two Languages Joomla Site (EN/DE) Which runs perfect.
I set up the Virtuemart also in German and English. German is my default language.
I have just one Category and about 30 Products.
Now i copied a Product and set the language to "English"  and save. But the language jumps always back to my default language German. So i can not save any product in the 2nd Lang EN language.

Any idea where i made the mistake?