Hello Ms Ellie,
If you have made sure the needle is a good one and in the correct way round the chances are you will need to retime the machine, I can attach timing instructions for you if you email me but this site no longer allows email addresses to be shown but you can get my email address from any answer from page 25 down or type this address in as you read it not as you see it.
drivewithken at blueyonder dot co dot uk
drivewithken
May 2009