Thanks for your replies. I will check the bottom hook out. Also the "manual" has details on timing the machine, so I'll check that as well.......but not adjust or touch anything until I'm sure something is not right. I'll ask here first.
Dan, I'm trying to source a welt foot here in Adelaide. Failing that I'll get onto the "net" and buy one O/S. How different are they to a regular foot ?. I've not actually seen one. Can a welt foot be made from a regular foot ?.