I have a similar issue. (OD+ on Win7 64 Ultimate) My docks simply wont autohide at any time unless i enter dock properties and make a change. Then the dock autohides, but then when i use it again, it stays on top till i mess with the settings again. I can have "always on top unselected and it makes do difference.
No combination of the dock properties get it to autohide..not even autohide.
SD, is this a known bug for Win 7? If so is there a update in the works, as this is very annoying.
Edit - Oh my...the Op was some time ago. oh well.