Disable all of your other addons which use AceLib, then check if it's still persists.
Edit:
I think 5 things could cause something like this:
hooksercurecalls (Mostly in combat)
StaticPopupDialogs (With non unique names)
UIDropDownMenu_SetSelectedName, UIDropDownMenu_SetSelectedValue, UIDropDownMenu_SetSelectedID, UIDropDownMenu_GetSelectedName, UIDropDownMenu_GetSelectedID, UIDropDownMenu_GetSelectedValue, fix here:
http://www.wowinterface.com/download...Menu.html#info
Initalizing dropdowns on addonload
Adding your addon into Blizzard Interface panel with leaks