iOS How to avoid 'Deep Sleep'

Hi,

Any idea on how to disable the 'deep sleep' mode the iphone goes into after a while?
I know that idleTimerDisabled can avoid sleep mode totally but I want the phone to be able to lock/dim the screen and keep running (just the way aol radio/imeem/etc) do it. It seems that no matter what I do (tried opening a connection when I receive applicationWillResignActive), it still goes to sleep and I stop getting incoming events.

I've searched the forum and it seems like the same question was raised about a year ago but never answered...

Thanks.
J.