I hate when someone says "DON'T SEW OVER PINS" because I do it. They act like the machine will self distruct or something.
In the recent June/July 2007 Sew News magazine, however, is the most rational explaination of why you shouldn't sew over pins I have ever read. On page 18 is a column by Sandra Betzina, Sewing Solutions, and she writes "Don't sew over pins except when cross pinning to avoid shifting joints. Sewing over pins can cause a drag on the bobbin, which weakens the seam. Sewing over pins can also dull or bend the needle".
I always do the cross pinning and sewing over and I believe it causes undue frustration to worry so much about pulling them out just in the nick of time. But she also points out, without all the doom and gloom, that it can bend or break the needle as well as drag on the bobbin.
I almost didn't finish reading the column when I read the "don't sew over pins" part, but I'm glad I did. I appreciate a rational approach to a familiar subject.
I actually met Sandra Betzina once, sort of. I was working in Christine's booth at the American Sewing Expo in Novi, MI. She came to the booth looking for Christine and found only me, since Christine was off somewhere schmoosing or lunching. Sandra is an extremely charismatic person. I'm a little socially inept anyway, but she rushed in and shook my hand, said some nice things about Christine, and buzzed off leaving me a little spellbound.
I doubt I'll ever register in her memory, but I'll never forget that moment.