sewing machine problems HELP!

I'm having a nightmare with my sewing machine.
When I'm sewing say with zigzag stitch its missing stitches therfore not zigzaging. Its doing this on other stitches too. Streight is fine though

Any one have any sugestions as to why this is happening?

are you sewing stretch fabrics? if not what are you doing exactly

stretch fabrics need a new blue tip [non stick] needle frequently

its a ball point needle you need for knit or interlock so it doesnt split the knit. Failing that, the needle could be blunt or bent, or its not inserted properly, take it out and reinsert it making sure its pushed up as far as it will go when you screw it in. Make sure when you drop your bobbin in the spool the thread forms a "q" not a "p".. exception are some top loading bobbins.. but you can remember which one yours is by the p's and q's

ps.. http://puddlekins.com/pfaff/schmetz%20chart.jpg

Thanx ladies.

x