If the new mixer resembles the old, the key is in the routing and the chosen default driver for the output.

In the old mixer it is the 'Monitor Mix' selection that can be used with certain routings and cause stuff to loop back thru. I don't yet know what it's called in the newer M-Audio mixers. I use outputs 1&2 as default driver in RB, seems easier to control.
Glad this problem is solvable. I've been considering that card .. thanks for posting.

I do not work here, but the benefits are still awesome
Make your sound your own!