I use Slacker on my BlackBerry practically every day and I am really liking this new v4 that just came out. It fixes many of the bugs I have found in the app though it takes a little longer to start. This new version 184.108.40.2066 improves the startup time a bit which is nice. I do not know what else is new in this update but let us know if you spot anything!
Download the update at www.slacker.com