Fixed now, Jeremy. It was a file naming issue: you had named drawing 3 as Lab_ and the others as LAB_ and I didn't notice this; since the names appeared to be the same except for the number, I simply copied and pasted each filename in the hyperlinks and changed the number accordingly. (Unix convention, don't you know: case sensitive, unlike Winders, so the system looked for LAB_18mm_drawing_3.dwg and didn't find it.)
Good show on the PDF's, send them to me when you get them done and I'll put them up.