Why is my MacBook Port Scanning UDP Port 7238?

I have a MacBook 2.0 GHz. Just got it March 20, 2006. I'm sitting here at work, minding my own business and a PC co-worker says I am port scanning him. This has happened several times over the past month. This latest I tried to port scan UDP Port 7238. I had Mail up, Firefox, and had just launched NoteTaker and NoteTaker informed me it had an update when he said I was port scanning. (It was my IP.)

Does anyone know what is going on? This happened last year from my G5 at home. My ISP kept knocking me off. (We have wireless.) They kept telling me I was scanning their Port 0. No, I was not! Finally, they sent someone out and they configured my D-Link router so it would not Port Scan particular ones. It's been about a year and I've not been knocked off since. It was a weekly thing back then.

Nancy S.