Printing Errors or Lights & Stuck Print Jobs

When printing note cards with the Avery 8315 card stock the stock won't be picked up by the feed mechanism after trying for quite a while. It then shows the out of paper indicator. It used to work smoothly without fail, but now may print several cards, but then won't pick up the stock and says it is out of paper. Once it fails it won't do it at all. If I load one or a dozen sheets of the card stock at a time it still does it, although most recently loading a single sheet worked, but when I flipped it over it didn't work. Several tries resulted in it finally printing. I checked to see if there was any stuck paper or scraps of paper in the feed path but none were found. I took off the back section that allows double sided print and see nothing wrong there. Is it possible that paper dust has built up and compromised the feed path. If so, how do I clean it? Any other suggestions would be appreciated.