What would cause a tick sound when putting down my power window?

I have a 99 Volkwagen Jetta and just recently noticed that my driver's front power window when about halfway down makes an obnoxious tick sound for half a second, and then makes the same sound when I put the window back up in the same spot. I just had the car in last week for a power window switch replacement so I would imagine if there was an issue with the cabling or anything else they would have told me (especially since I mentioned this to them). While they were doing the repairs they said they didn't hear anything out of the ordinary and when I picked it up it sounded just fine but over the weekend after the car had been out in the cold I heard the sound again and its been there ever since. The window itself goes down just fine, comes back up just fine there is no slow down or stuttering when its functioning. The tick sound seems to be coming from where the window goes down into the door where the weather stripping is, I'm not hearing any tick sound or weird sounds from down in the door itself anywhere. I also noticed that where the window is when the sound occurs there is a scratch in the window on the inside. Could that scratch in the glass be causing this annoying sound? And why would the sound be intermittent, it seems like its more noticeable when its cold out.