[Natty] Gaia unusable, no gui is rendered (SimpleTileStorage: error)

Binary package hint: gaia

When starting the program, I get this Output:

nordlicht@Demian:~$ gaia
1300465229.195582 SimpleTileStorage: error (wwfetch_fetch_image() failed) (0 0 0)
1300465230.638720 SimpleTileStorage: error (wwfetch_fetch_image() failed) (0 0 1)
1300465232.083970 SimpleTileStorage: error (wwfetch_fetch_image() failed) (0 1 1)
1300465232.431952 FPS: 60.187962, frame time 16.614618 ms
1300465233.522847 SimpleTileStorage: error (wwfetch_fetch_image() failed) (1 0 1)
1300465234.994132 SimpleTileStorage: error (wwfetch_fetch_image() failed) (1 1 1)
1300465237.449348 FPS: 60.195336, frame time 16.612583 ms
1300465242.450041 FPS: 60.187962, frame time 16.614618 ms

The Program starts, but I don't get a usable interface. I've taken a screenshot, it shows only a grey window without any elements.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gaia 0.1.2-6
ProcVersionSignature: Ubuntu 2.6.38-7.35-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
Architecture: i386
Date: Fri Mar 18 17:18:13 2011
ProcEnviron:
 LANGUAGE=de:en
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gaia
UpgradeStatus: No upgrade log present (probably fresh install)