Odd polling type behaviour

Hi

Just finding an odd situation with our application where it appears to do something like a poll periodically when the browser window is just sitting idle with no user input. I have setPollInterval to -1. I added a poll listener and it is not fired by the odd event. By event i mean the little blue line that shoots across the top of the browser (which happens on poll usually, or a refresh etc)

Im not sure what is happening here

Thanks

My bad. Was part of my implementation of a javascript timer.