Problems with driver side power windo

About 6 months ago I replaced the power windor motor on the driver side door. Now it seems like it jumping a tooth on the gears. Do I need to lubricate this gear. I had it replaced at my local glass shop. Or do I need to replace something else. :screwy:

Just got it fixed. Turns out it was the window motor again. I suggest to every body to buy a good quality motor if they ever need to change it. I bought mine on ebay because a dealer part was costing me $160. I ended up spending more than that. I wished I would have just bought it at the dealer originally. at least that way I would of been covered by a factory warantee. :disappoin