Printing with roller on P800 with Elements 10

When printing using Epson P800 printer with roller & set to custom size in elements 10 the printer seems to stop, then print a repeat ghost image of final cm. then ejects another clear whole length of the custom size paper. Epson engineer has attended and has proved that it is not the printer as it prints correctly from his laptop (not Elements). This only happens when using the Elements custom size option. JD