Hi Lyn,
First thing to check is the condition of your sponge bars. If they do not have enough foam - at least 1/4 inch - above the metal bar, the needles will not be held down properly and although they will knit when using the main carriage, when you try to use the ribber problems will arise.
Are you trying to knit rib? The ribber connecting arm will not knit stocking stitch very happily as there are no wheels to push the fabric against the sinker posts. You need a lot of weight to help the stitches knit off properly.
If you are trying to knit rib, make sure the ribber carriage cam levers are set to N and the tucking lever on the tension dial is set to R. The holding cam levers at the side of the ribber carriage should be set to =.
Also make sure the connecting arm brushes and the yarn feeder are aligned properly and that both latch opening magnets are in place. Finally check that the connecting arm is seating properly on the main carriage before you tighten the thumb screws.
I hope some of this helps but do check the sponge bars and replace if necessary.
Regards,
Sue, December 2010