I ran a game using Roll20 in a Google+ Hangout. My browser is Firefox 12.0 and my operating system is Mac OS 10.6.8
I found that there was often a considerable delay in executing any instruction given with the mouse, during which my cursor changed to the coloured whirly thing that indicates that the computer is busily calculating. This seemed to get worse as the evening got on.
Indeed, towards the end the mouse cursor would sometimes turn into the whirly thing spontaneously, without my having done anything. I asked my players whether they had done anything that might have set my computer to processing anything, they said not.
