[SOLVED] Product variation with multiple atributes problem - changed first atribute change second atribute

I have product variation with atributes: color (red, blue, gree) and size (S,M,L).

The problem is:
For instance customer select red color and size M. After initial selection customer change color to green - size changes to S! The customer must correct size back to M. But I need size to stay in M and do not change from initial customer selection!
Do you now someone what I have wrong? In last Commerce Kickstart it works OK, but I do not know where I make mistake in configuration.

Thank you very much,

Posted: Feb 21, 2013