Having sound issues... :l

I'm having a problem that a search on google cant seem to answer..

So I have an MBA that I have connected to a 32" tv to run as my monitor (thunderbolt to HDMI), and also have my MBA connected to my interface via usb (focurrite scarlett 2i4).

I use Pro tools 10, but when I run PT10 with the hdmi plugged into the tv, the sound comes out of the tv.... I need the sound to run through my interface only (headphones and speakers)

is this possible?

Note: I've noticed that when I run PT10 on my MBA before I plug in the HDMI it works on the MBA just perfect and the sound comes through the interface only...BUT...As soon as I plug in the HDMI to the TV, PT10 starts to act real wacky (cant scroll or add notes).
Now if I plug in the HDMI before I run PT10 on the MBA, PT10 works fine but the sound will only come out the tv. PT works fine.

I need PT10 to work smooth and the sound to come out the interface only.

Does anyone use a tv as a monitor and have sound coming out the interface??


:confused:

Thanks in advance!