BBM beta for Windows Phone sprays Raid to exterminate bugs7
The bugs taken care of include: Restarting BBM brings up the "Find friends" screen intermittently, BBM crashes when trying to add an image when adding a post, Feeds tab does not display splat on Channel or Contacts updates, Unable to add screenshots when adding a post with an image, Newly created Channel appears with a join icon on search, BBM freezes after sending or receiving a Sticker and BBM is slow to load featured/owned/subscribed Channels on HTC devices.
Unfortunately, even with the elimination of those bugs, the new build also has a number of known issues including one that crashes the app and prevents the user from creating a channel with the Nokia Lumia 530. Since this is the most popular Windows Phone of all time, it might behoove BlackBerry to make certain that this problem is fixed before releasing the app out of beta.
source: BBM (WindowsPhone) via Crackberry