Google Maps display divided in squares on Iceweasel

[Elio]

The Google Maps display is divided in squares separated by a grey zone.
On fullscreen on my display (1920x1200) squares are approx. 6 1/2 x 3 1/4.

System information:

Dell Inspiron 9300 running Debian Sid 
ATI Driver 8.42.3

$ fglrxinfo
display: :0.0  screen: 0
OpenGL vendor string: ATI Technologies Inc.
OpenGL renderer string: ATI MOBILITY RADEON X300
OpenGL version string: 2.0.6958 Release

$ uname -a
Linux prometeion 2.6.22-elio.6 #2 Sun Nov 11 21:59:04 EET 2007 i686 GNU/Linux

$ iceweasel -v
Mozilla Iceweasel 2.0.0.9, Copyright (c) 1998 - 2007 mozilla.org