Whenever I use mumble while also using headphones my computers sound starts going screwy. All the mumble noise goes through my headphones, but the rest of the noise goes through the speakers.
Plz halp.
There are some free online thingys that let you play mtg, you may want to look into them.
I really oughta get one of them at some point. I haven't used one since Cockatrice ate a copyright infringement thing from wizards.