Blizzard released a minor patch yesterday to correct some in game issues.

Bug Fix Patch 1.5.1 Released
A small bug fix patch will be applied later today to fix two outstanding bugs (listed below.) This patch does not require any realm downtime, and will not interrupt game play.

Bug Fixes

- Fixed an assertion that was preventing Mac clients from playing in the battlegrounds and causing a memory leak on PCs when they did.
- Improved error reporting to give more useful information to development.