Bricscad V11 on Ubuntu 11.10 Critical Error

Hi, after running Bricscad in Ubuntu 11.10, I try to open a file .dwg, but it freezes.

Launching from terminal, among others, it returns the following message:

Gdk-CRITICAL **: IA__gdk_drawable_get_depth: assertion `GDK_IS_DRAWABLE (drawable)' failed

What's wrong?

Tnx.