Obsol3te

When pushin the button to roll down my driver side window.
The little water sealing rubber thing catches as the window goes down.
Sucking the rubber thing down into the window making the window stop.
So I have to roll it up a bit then roll back down.
Any1 know what I can do to fix this?

The rubber thing I'm talking about is the lip-like thing that makes it so no water gets in.
The thing that touches the window itself.

Don't mind too much but its annoying as hell. Any easy fixes?
Or just replace the rubber thing.