Has anyone had success printing synthetic non tear paper through the Iridesse? We've done some test sheets and we can match the colour when printing duplex, the reverse side comes out completely different? We also get patches of colour inconsistency, as if the toner is not completely adhering to the paper. The engineer team have been in but have had no success either. Do we print one side only and then run it again to print the reverse? Worried about alignment if we do that? Any suggestions?