Thanks for raising the issue with Croteam.

(In reply to Germano Massullo from =
comment #14)
> I've just double checked and we definately set G=
L_DRAW_FRAMEBUFFER to 0
> (default back buffer) before clear.

When I look at the trace from comme=
nt #10 in qapitrace, I see a bunch of
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ...) calls in frame 0, the last one
being

 glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 31)

After that, there are no glBindFramebuffer calls for a long time.
GL_DRAW_FRAMEBUFFER isn't set to 0 before frame 777, after which the flicke=
ring
stops, and the window contents start looking as expected.

I've now also confirmed this with running glretrace in gdb and setting a
breakpoint at _mesa_BindFramebuffer.

I'd definitely like somebody else to confirm the above though, to make sure=
 I'm
not missing anything.