Mine will do that about once every three or four months. Can't figure out why, just hangs on loading. I tried everything to fix it, (signing in/out, battery pulls, checking/deleting message on pc, etc)nothing worked. so I just delete the app and re-download. Clears it right up and works perfect until it hangs on a message again. (On mine, 3-4 months)
Hope this helps.
I would uninstall, reboot and re-install myspace that worked for me the one and only time I have that problem.
It sounds like your mobile app it the issue if its gone from myspace because you have deleted it via you PC but your app is getting hung trying to read it because some how the notifyer may have gotten corrupted.
i work for myspace, and i still have to uninstall & then re-install to make it go away. so annoying. it only happens when someone else with a blackberry sends me a message from their myspace blackberry app.