Yes, many people have told me the same thing. If the index unit lines to the next row down are not straight they can manifest themselves and be well and truly off the mark at the end.
I use a pacer pencil which I think should come with a warning. Just this arvo I was feverishly working a trim sheet and dropped the pacer, went to catch it and managed to stab about 15mm of the bastard straight into my left thigh. Thank Christ we have tweezers in the house, got the piece out with a few P's and Q's for pain relief!