I can't cache slacker radio stations on my BB. I connect it with mass storage mode but there is no option for caching in the box that appear with the actions options. when I go to my computer and click on synclauncher.exe for slacker, I receive a "window cannot open this file" error message. I have windows xp. Has anybody had the same problem? Any help would be much appreciated.

I would try removing the cached station on your BlackBerry. Delete everything from Slacker on your media card while connected in mass media mode and disconnect. Do a battery pull, then try caching station again, connect and see if it works then.