To be able to play and record at the same time, a card needs to be full-duplex. As far as I know almost all of them are these days, but the Allegro is a really basic sound system, so maybe it doesn't?
There is also a place in the Audio options, I believe, where you can enable/disable full-duplex operation in a card that is capable of it. It's possible the Allegro is ful-duplex but this setting is toggled to disable...