Water building up on window track

We have large sliding windows in 2 of the bedrooms in the house and I found that one of them has water that seeps onto the inside track but does not go over. Eventually it drains out when it stops raining but leaves dirt behind. I looked at the weep holes on the outside of the window (did a google search) and they are not clogged. I called the company that manufactures the window and they told me it would cost $75 just to have someone come look at it. Just wanted to see if anyone had any idea in why this might be happening. Thanks!

Re: Water building up on window track

I have the same problem on one of my sliding doors ( Pella ) would love a solution.