Problem with Ricoh GX3300, lines appearing on print

[magicfingers]

Using inks from BMS, printing from Adobe Illustrator CS5 on a Macintosh running the latest version of Lion, using standard adobe profile.

Today we started getting lines appearing on our prints. I've done a nozzle check and everything looks good, done a head clean and it's still there. It appears for all inks. Any suggestions what might be causing it? The printer is quite new, we're on our first set of inks. Pics below show problem

[bms]

Is there something caught in the printer causing this? Usually lines go horizonally if there is a printhead problem. Have you tried performing the head alignment check?

[magicfingers]

The lines do go horizontally. We're printing on to pre-cut paper for mug printing. Yes, we checked the alignment and everything looks good. The lines vary in how bad they are from print to print.

I take it the head is independent of the ink cartridges?

[bms]

The lines do go horizontally. We're printing on to pre-cut paper for mug printing. Yes, we checked the alignment and everything looks good. The lines vary in how bad they are from print to print.

I take it the head is independent of the ink cartridges?

Ah, sorry the images looked like they went the other way!

Yes the head is independant of the cartridges - there are 2 heads in the Ricoh printers. Can you create a square of 100% C, 100% M, 100% Y and 100% K (4 squares on 1 page). Which of the 4 squares has lines in it? Make sure you have 100% of just one colour (you can do this in Photoshop) so that you get an accurate idea of which head is causing the problem...

[magicfingers]

I'll get that done tomorrow and post up the results, thanks.