There have been a few times I have cried at work, and in front of someone no less... One time was when we lost a coworker to a tragic car accident (enroute to work on a Sunday to meet a customer), another time was when I was so frustrated with a coworker and had to take a vacation (and that was teared up - but none flowed until I left the presidents office) the third time was when I got chewed out by a boss known to tear someone down - and that I held in until I left his office (he later apologized for being a jerk and totally out of line).

I think we've all cried at work at one time or another... and yes, people get VERY uncomfortable when dealing with weepy people.