Is there any way to smooth out the animation?
It doesn't seem to matter what AnimationSpeed setting is used.
I have not seen this. Is it possible there are many controls on your form or dock pane which are repainting when the pane moves which might be causing a performance bottleneck?
It depends on your definition of "many controls".
Are there any painting events I can turn off?
It appears to be related to the complexity of the controls that are not on the docked pane.
As a test, I removed the controls on the main area of the form and it closed just fine.
I will submit a sample as time allows.
I guess it depends on how complex the layout and display of the grid is, but it's possible it is a bug. I would recommend submitting a sample demonstrating the issue to the support group if possible: http://ko.infragistics.com/gethelp.