It didn't affect my computer running OS X Lion (MacBook Pro from early 2011). I just recently upgraded to mountain lion so I'll test it out. That'll limit it down to either an OS issue or a driver issue.
Desktop:
OS: Windows 7 64 bit
CPU: Intel Core i5 3570K @ 4.4 GHz
GPU: EVGA NVIDIA GeForce GTX 550 Ti (Factory OC'ed)
RAM: 16 GB @ 1600 MHz
Dolphin Revision:3.0, 3.0-784, 3.5, latest 3.5
OS: Windows 7 64 bit
CPU: Intel Core i5 3570K @ 4.4 GHz
GPU: EVGA NVIDIA GeForce GTX 550 Ti (Factory OC'ed)
RAM: 16 GB @ 1600 MHz
Dolphin Revision:3.0, 3.0-784, 3.5, latest 3.5