"Save config" in rviz doesn't work on OSX

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Finally I've managed to get ros fuerte working on OSX. Still there's a bug when saving the config with default extension .vcd within rviz. Starting rviz, it loads the config file ~/.rviz/display_config by default. When I use "save config", I'm not able to write ~/.rviz/display_config. Instead, the file is saved as ~/.rviz/display_config.vcg.

In my opinion, the correct default file should use the .vcg extension. Any other opinions?