I have no idea why a double click on the map would affect the tabs.
I really think it's because that jsMap code is just too arcane to be useful.
I can't understand why anybody would use multiple layers for zoom control in any case. Even if it was originally designed to just be used with one image per layer, that still makes no sense. Just start with one image at the MOST zoomed in level and then it's trivial to zoom it out with no layers at all.
I truly think it's time to dump jsMap.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.