Printing problem


I am making a POS software for my own use
using Ruby-Gtk and now I’m in trouble with printing

I need to print to 9.5x5.5in continuous form paper with Epson LX-300+
I use this sample I found on Gtk::Print* sample program - Ruby-Gnome 2 - Ruby-Forum
I change paper size and margin to fit my need

in preview, it looks perfect. When I print, It prints nicely.
But after print finish my printer pull paper to size about A4 or letter,
twice length I need

I really need it to stop pulling paper at the end paper size so I can
the paper and continue print next page
How can I fix this?