sometimes pyglet forgets to call on_draw

[GoogleCodeExporter]

What steps will reproduce the problem?
1. cd examples
2. image_display.py pyglet.png
3. A window appears, showing the pyglet logo
4. Cover half the pyglet window with other window (using mouse)
5. Uncover the pyglet window (using mouse)

6. The pyglet window remains dirty.

Clicking in the client area or dragging the window using the title bar don't 
refresh the client area, pressing a key or minimizing and restoring redraws the 
client area. 

Any additional info (platform/language/hardware) that may be relevant?

winXP sp3
python 2.6.6
GPU integrated intel 945G
(confirmed also with integrated nvidia 6150SE )

Another script with same defect is examples/html_label.py

I also see the defect in a cocos sample script.

The common thing to all those is that neither schedules anything, other scripts 
in pyglet's examples or cocos's test that schedules some function don't show 
this defect. 

Original issue reported on code.google.com by ccanepacc@gmail.com on 23 Mar 2012 at 4:32

[GoogleCodeExporter]

sorry, forgot to tell that this was with pyglet 1.2dev, as in

D:\hg_externals\pyglet_12dev\examples>hg summary
parent: 2632:f407d228a880 tip
 stop using [NSWindow center] to center window
branch: default

Also, pyglet 1.1.4release don't show this defect.

Original comment by ccanepacc@gmail.com on 23 Mar 2012 at 4:35