Multistalker unhandled exception

Hi folks. I recently installed Multistalker on my box and it works fine when i put only one portal config in it. But, if i put more configs 2 or more, i this specific case 5 portals that all works fine, only one of them can be opened, the other 4 when i switch the configurations want work and there is error message "mutistalker unhandled exception". What could here be the issue? Thanks