smooth table scrolling + IO

I'm facing a serious problem in smooth scrolling of my table layout view. I've got some IO operations taking place in the service binded with an activity. The activity seems to have some lags in scrolling a table layout when the networking operations take place. I have no idea how can I agree the IO operations in another thread with scrolling the view. Of course I know how to you sync threads but the only thing which comes to my mind is to wait when the user starts scrolling, then make the IO thread waiting till it's over and continue IO after that. However I don't believe it's a perfect solutions because I've seen many apps in the android market that are able to scroll and query http simultanously.

thanks in advance for any tip