Hi,
looking at the user map again I noticed two extra things:
* the initial loading is a little slow on a real internet
connection. This does not surprise once I look at firebug,
since the following javascripts have to be loaded:
- OpenLayersSFB: 244KB
- VespucciSFB: 99KB
- XinhaCore: 92KB
- firebug.js: 20KB
- Jugl.js: 14KB
that is, 469KB worth of javascript. Can this be put on
a diet? I'm quite confident you don't need all of that
OL for example.
Also, looking at the HTTP headers, the javascript has not
been gzip compressed by Apache... this could be a win
as well
* Try to open history, then click and each red marker
(developer) on the left in order, do not close the
popup. Then start zooming and moving around.
Some extra red markers will show up in the map and
you won't be able to get rid of them, nor to click
on them and see who they are... it seems to me
some extra drawing is left in whatever canvas
OL is using to paint the markers
* try to do a shift-drag to zoom in. The window extends
of the current selected area won't show up, you're
zooming in "blind"
That's all for today 
Cheers
Andrea