In the middle of printing a job, when the head returns to the station to get cleaned, the wiper will come out to the front, and an error will appear (WIPER ERROR), then will ruin the job. Then will will ask for the roll size (as if I just loaded the vinyl). Any ideas of whats causing this or how to fix it? I have cleaned out the wiper motor (from the rear), so I do not think "Gunk" is the problem..... Help is appreciated! Thanks in advance.