Thank you all for the advice, and the smiles
I have indeed lowered the pressure on the walking foot - seems to be helping.
I've also had a rethink about the plan of the quilting lines, and have created a pattern that rarely crosses other lines. So each block is being quilted separately in a kind of snail shell (with corners LOL) moving from the central small square towards the outside edge. In this way the quilt line only twice meets or crosses another line, where the main problems were occurring.
It does involve an awful lot of moving the quilt around and around under the needle at each change of direction, but so far (done 2 blocks so far) it appears to be working okay. I also changed the thread colour on the back (same weight) so make the lines les visible. There were meant to be a 'feature' but they were an eye-sore
As it's a hand machine I am going slowly, well very slowly to be honest, and I'm glad to have the individual stich control it give.
Many thanks all
Leila