Owners of the Vicarious Visions-developed Wii version complain that the game's promised Dolby Pro Logic II mode does not function properly, and only outputs through the center channel. Meanwhile, stereo mode appears to provide the same music to both speakers, essentially making it "dual mono."
A detailed analysis by member kurty shows that, in the single-player renditions of Santana's "Black Magic Woman" and the beginning of Foghat's "Slow Ride", the left and right channels of the songs are exactly the same. According to kurty, only the Vicarious Visions logo and game's crowd noises are in true stereo, with each speaker receiving a different signal.
E-mails posted within the thread indicate that Activision Customer Support is aware of the issue and is currently looking into it, though no potential fixes have been suggested.