Problem with HL-L2400DWE

[pchristyUK]

This is a wireless printer, so I can't submit the USB details requested.
OS: Slackware64-current Printer HL-L2400DWE
I started using brlaser v6 late last year after buying the above printer. For the most part it worked well using the HL-L2360 driver, but it would occasionally throw up "out of memory" errors on multi page documents,most noticeably PDFs. I have just upgraded to version 6.2.6, which seems to have cleared the "out of memory" errors, but now, when printing double sided pages, the even pages are completely corrupted. The odd pages print fine, but the even ones resemble streams of bar-codes. In addition to the 2360 driver, I have also tried the 2300 and 2390 drivers, but all produce the same problem. The same files print to an inkjet perfectly.