How can printer cut off paper when printing Sales Receipt?

intelcore2quad88

I have problem when printing Sales Receipt by printer at POS. I have used NAV 2009 R2 and LS Retail 6.2

When I print Sales Receipt by virtual printer, everything in layout is OK, but when I print Sales Receipt by printer, printer cut paper before printing footer. So I think function (in Codeunit POS Print Utility) which is used for printing footer have problem than I lock this function and print again. At this times, printer cut paper after printing TOTAL line. I don't know how does printer know to cut paper exactly ?

Thanks everyone.

Savatage

We don't use LS Retail - but here's a post about adjusting the CU for printing.
viewtopic.php?f=23&t=17593