Any news on that odd behaviour anea?
Aye :) I answered before but maybe I wasn't fully clear on it:
Basically: after changing growup/growdown you need to do a reset as well. After that you can drag the pane to where ever you want it to be and it will work as intended.
The problem has to do with the way the game handles anchors. I'm including the reset as an implied function to the growup/growdown option in the next release.