Overture-Demo and Nvidia: BadLength (poly request too large ...)

[fanumbra]

This is about the Overture Demo which fails to start on Debian Wheezy AMD64 with Nvidia 6200 TurboCache video card.
This happens since I replaced my nouveau driver by the original nvidia driver.
(I replaced nouveau because the demo start menu was extremely slow, even the mouse pointer was stuttering.)

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Now, with the original Nvidia driver, the screen becomes black for some seconds, then reverts to my terminal (with the screen resolution already switched down), and I read:

Code: (Select All)

X Error of failed request:  BadLength (poly request too large or internal Xlib length error)
  Major opcode of failed request:  128 (GLX)
  Minor opcode of failed request:  1 (X_GLXRender)
  Serial number of failed request:  405
  Current serial number in output stream:  408
Penumbra: Overture exited unexpectedly, please check
/home/rr/.frictionalgames/Penumbra/Overture/hpl.log
for any error messages
Also try running
ulimit -c unlimited
And re-running Penumbra and try and recreate the error
then submit the generated core file or stack trace

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ulimit -c ... did not change anything.
The hpl.log shows no error just some "success" messages.

How to continue ?
Thank you in advance -
Ruben

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(The full hpl.log is attached.)