3d rendering problem in walktest

When I run walktest with map partsys..the output is normal..

But when I run walktest with default map castle...the rendering has some
issues.

I'm attaching pics for both...
First four are from castle
next two are from partsys

I ran the programs on arch linux system with mesa 10.0.3-1
The following video cards are present
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics
Controller
NVIDIA Corporation GF108M [GeForce GT 630M]
mesa drivers for both are installed
nouveau-dri 10.0.3-1
intel-dri 10.0.3-1

Also the system has 8Gb RAM and has intel i5 gen 2 processor

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Ayush (irc alias merci)