popup menus misplaced on linux-fb

[Benjamin <thronerbe gmx de>]

hi,
   i am using gtk 2.6 on a patched linux-fb, so it runs on an ordianry 
framebuffer (in my case on OpenGL).
   most things work fine so far, but the popup menus a drawn "slighly" 
misplaced (see atatched screenshot).
   lets say the menu pops up at x,y then the primitives wich the popup 
is made of (lines, pixbufs, etc.)
   appear at 2*x, 2*y. this is the case for popup menus and the 
selection men�ombo-boxes, others
   i don't have tested yet. does have anybody an idea why this happens?

   another thing (less important to me at the moment) is the blue 
background, sometimes it has the right color,
   sometimes it is blue, straaange.

thanks in regards

Benjamin