Help!: Much Slower when in map EDIT mode

So one of the things I've noticed is that my maps load fairy well initially. But when I click "EDIT" the map attempts to reloads and is virtually useless in terms of how everything crawls to a snail's pace. By slow I mean that it might take 20 seconds for the map to load in the edit mode... and then something as simple as zooming-in the map one tick might take 20 seconds (with the "spinning beachball" delay while things load).

I assume it's due to the fact that much more data needs to load to make the map editable. But this renders the map essentially useless.

Is it just me?

I'm on a MAC/G5/dual2ghz/2gb-ram/Firefox2.0.0.4

thanks,

Victor