Inconsisten movement speed of the viewport

[mape2k]

I did some more research today and I found out the cause, which is quite interesting:

When I use one of the envorinments provided by Vizard (i.e. ground_grass.osgb), everyworks fine and the movement speed is correct, both automatically and manual. Also, the viz.collision setting has no impact on the speed.

Whe I use one of our own environment (also just a simple ground plane with a tube around it to create an arena) and I have viz.collision turned OFF, everything is working fine.
However, if I turn viz.collision ON in our environment, the movement speed while moving with the keyboard or the joystick if off by about 0.5m/s for a speed of 10m/s. When I move automatically in this setting, everything works fine.

Jeff, I have send you a private message with a minimum example. In the first phase, the viewport will move automatically for 100m. Then, the viewport is reset and you can move forward for 100m with the key '3'. The position and time is logged in a separate .txt file.
In the first lines, you can switch the collsion on and off as well as change the environment from a standard one to the one that is provided with the .rar file.

Thanks for your help!