Power window keeps getting stuck down

[strep3241]

I have a 1998 Chevy s-10 and every so often the driver side window will get stuck usually in the down position. All I have to do to fix it is take the window motor off and put it back on and it will work fine for several months or longer but will happen eventually happen again. When it works, it works fine.

Why does it keep doing this? Is there something I can do to prevent this?