Large file print loop

I use redhat 9 with cups 1.1.17-13;
if I print a large text file (~40 pages)
with "lp -o ascii -n 1 -s -d print_name file_name"
the file is printed continuously, until when I do "cancel print-job".
Small's files are printed correctly.

The two printers are connected with parallel port on a print-server.

Any suggestion ?

Thanks
Stef