XnView Software

(xnViewMP v0.61 on Windows7 x64)
Drag the toolbar on the left side in vertical position, go to Tools > Settings, make some changes and click OK in settings dialog.
Toolbar will jump into default horizontal position, instead of keeping previously defined vertical position.

Still same in xnViewMP-64 v0.84
To reproduce:
1. Drag toolbar to dock it wherever you like, but not in default position. Or leave it floating.
2. Open Settings window and close it with OK.
-> Toolbar will jump back to default horizontal position.
Annoying.

Bug confirmed.