Maybe you know about this bug already, but here is a simple way to reproduce the bug. It is with the fast (animation-less) window move.

Version: 3.2.0.106 (beta 6)

Steps to reproduce:
1. Maximize window (on any monitor)
2. middle click on titlebar (moves to next monitor)
3. minimize

Step 2 works as expected.
But after minimize, the taskbar item goes back to the original monitor (same monitor as step 1).

Attached debug log (enabled debugging just before and after reproduction steps). Specs in my sig.

Whoop. Just upgraded to Beta 11 and it seems to be fixed. (even used the advanced setting in registry)