is my edirol UA-25 that i just bought faulty?

i just bought an edirol UA-25 and the MON.SW button does not toggle when pressed - is this right? i went and left the manual on my desk at work so don't even know what the button is supposed to do but if it's dodgy i need to send back asap. all the other buttons are toggle ones that remain depressed if desired except this one on mine is acting like a momentary switch (only on when actully being pushed). if anyone knows and could help me out that'd be awesome, cheers!

think i've worked out whats up - the switch is fine there's just no click and it doesn't remain in, phew! it toggles a wee light. not worth sending back for that. still no idea what a MON.SW button does but this wee thing sure does sound good! it's my first decent soundcard really - combo of dirt cheap and onboard sound thus far. it definitely pisses all over the previous things i've used (but not by as much as you might think) and it solves the problems i had with a cheaper one picking up mboard noise from the laptop. my only criticism so far is that the extra clarity leads to me hearing more bits that i need to improve in my tunes.

i have an FA 66. can get frustrating sometimes...as much lag as my shitty usb Audiophile...but its as durable as a tank.