I played the entire campaign, no problem, and I played matchmaking during the beta (except for when the beta didn't work on macs).
Help? I didn't see this issue in any other posts.
Running SC2 on OSX 10.7.5, on an older Mac Pro. 2 x 2.66 Dual-Core Xeon, 10GB ram, ATI Radeon X1900 XT.