Strange Aperture iMessage interaction...

Hi;

I observed interaction between Aperture and iChat. It is easy to reproduce for me. If I select new empty space and open iChat on it. After that I open Aperture on the same space. Do some stuff in Aperture and then quit Aperture and iChat become damaged. Pane with buddies and conversations became blurred and gibberish. Only way to fix the problem is to restart iChat. This is not happening with other applications and Aperture and with iChat and other applications onyl combination Aperture and iChat. I cannot reproduce it on my latest iMac running same OS only on 15" Retina MacBook Pro. Any ideas? Can somebody out there try to reproduce problem? Thank you.

Marian