Horizontal space thru text.

I have a panasonic 2023 24 pin dot matrix printer that is spacing a horizontal line thru the text of the print job. Even on test page half of the letters are on one line then a space (line) then the other half of the letters.(splits the letter of the text so that an H would have a || on the top and another || two lines down) I have tried reinstalling drivers and still have no success. It is a win98 machine, updated drivers..(tried win98 and panasonic), tried changing bias settings..the strange part is that it worked last week and if I print thru the network to another of the same printers, it will work.