It sounds like one of two things is going on:
A. You don't have the sound blaster selected in MC's audio setup: Tools > Options > Audio > Audio Device > (select your sound blaster here)
or
B. Your sound blaster somehow does not support 44.1kHz audio. This would be unusual unless it's some kind of wireless system. If it doesn't support 44.1, I would convert 44.1 to 48kHz via the DSP studio. This seems unlikely though, again, unless it's bluetooth or something.
Brian.