Although I often switch between Slacker Radio and Pandora, the new services recently introduced by Slacker have caused me to use it more so then Pandora recently. The PlayBook app is great but the BlackBerry app for a while now has always some minor bugs within including a rather long start up time.
The latest version, while not in BlackBerry App World as of yet has been released via the Slacker website recenty -- having downloaded the v4.0.736 release it looks like start up time has been reduced if nothing else. Still, no change log has been posted but you'll likely want to grab it anyway if you're a Slacker Radio user. Thanks, to all who sent this in!