Snanner problem in printing office

My friend has a problem with scanning in her printing office.
I'll try to describe it as clear as I can:
The device's name is "XEROX DocuColor 12" and it is connected with PC over FIERY XP12".
She scans dociments with Photoshop 7 as follows: IMPORT.., FIERY... SCAN...and than little window appears where she click on PRESCAN and than the lamp on the scanner gets across the document and loading (prescanning) begins. At the end (about 100%), instead of preview picture, she gets message "ERROR...NO SCANER DATA EXISTS"!
She told me that this happened once before, but she dont know who fixed it. Some guy came yesterday and he said that device is properly connected, but he dont know why is scannin not working.
She tried with other PC but nothing.
Does someone have any ideas?