Ok - the bug was more obvious on that second movie you sent - I agree that the movement looks weird - slipping sideways like that.
I am not sure what is going on with XP11´s friction model, but the default 737-800 is behaving pretty good, I think. If you want to get Austin to look at the problem, you need to illustrate it with "default aircraft" - he won´t look at 3rd party stuff.
We will see what is going on with our model and XP11 at a later stage (when porting), and we will just have to deal with the way XP11 handles things. If we need to re-do our ground model, so be it.
Thanks for pointing this out, though!
Jan