The point of the unhide_delay is to keep the autohidden panel from opening
spuriously when the mouse happens to brush the edge of the screen. 
Currently, though, the delay is just a delay from the time the mouse
touches the edge to when the panel opens; the mouse doesn't have to stay on
the panel for the whole delay.  For example if the delay is set to 2
seconds, and the mouse brushes the edge of the screen where the hidden
panel is (say for 1/10 of a second) and then goes elsewhere, 2 seconds
later the panel pops up.  This  totally defeats the purpose of having a
delay, and makes the panel pop up all the time when it is not wanted.

To Reproduce:
1. Make an autohide panel
2. [optional] Set
/apps/panel/profiles/default/toplevels/panel_XXX/unhide_delay to somethiing
big (say 5000) so you can see this happen better.
3. Touch the hidden panel for as brief a time as you can, 5 seconds later
the panel will pop up.