Been seeing this for awhile...when switching taskbar from vert to horz(or viceyvercey)...the QL buttons dont change to the ones assigned to that particular config.
Its like they are stuck on whatever config was last used.They do correct themselves if you re-apply the skin but some users might not know to do that and just think your a lousy skinner...cant have that. 
Rebooting of course allows them to be correct...til you switch taskbars again.7,Vista and XP all do this I think...been awhile since I checked on XP.
A side issue...on 7 vertical taskbars there is a LOT of space under the start button before you get to the first pinned app buttons...like about 100 pixels or more.
I checked other skins and a few have less wasted space but not by much and I was unable to determine any difference that would account for this. 
Cant make a screeny of it just now...am on blech,Vista. 