I have the same isuse.
I'm using an Epson 9600, and under my Vista computer the Printer box in Page|Setup doesn't show up.
Under my XP Pro machine, the Printer button is definitely there.
This is a problem because the only way to switch page size on the Vista machine to a roll of paper is unde the Print menu, and it doesn't seem to use the changed page size - when you print, it still insists on printing at A4 size.
This is a serious problem as it negates the use of the Print Preview to check that custom page size actually works for the current chart.
I presume that this is a Vista / particular Printer driver issue - I don't have vista to check this out. It is likely that the currently selected default printer driver is the problem.