map center/zoom problems in ym4r

I am trying to show a list of events and their locations in a map in
my index action. I use will pagination for paginating through the
events. The first call to the page is a regular "html" format and the
subsequents calls are ajax calls. I initialize the map and markergroup
that contains the event markersin the first call to index page, for
subsequent ajax requests i bind the browser variables with the rubu
variables and add/remove event markers from the group. It all works
fine, but if lets say there are 2 markers 1 in new york the other in
san fran, i want the map to automatically adjust zoon to show all
markers in the map, but it just shows either one. if i call
"centerandzoomonmarkwrs" on the group then the map centers on east
coast of africa!

index action