DPM2340 Can't Be Found

I've had a DPM for several years now, it's been pretty much trouble free. It connects via SCSI to an XP machine (it originally came with an NT machine but I managed to get the software working on XP, minus some functions like temp monitoring). It's run fine on this for a couple of years, used it a few days ago no problem.

Next day I go to run it and the Printers RIP (v5) tells me the DPM can't be found. So, I've spent a whole day trying various things - different cables, taking SCSI card out/reseating, swapping PCI slots, uninstalling SCSI driver, loading new SCSI driver. I resorted to checking the SCSI BIOS which seems to report the DPM as being there. Edit: also tried SCSI-USB cable but the OS couldn't get that working (saw it as SCSI storage).

Just wondering what the best tact is? I can't find anything in the RIP's settings that might help. I can try reinstalling all the software, but it was a major hassle getting all the settings right with XP. The other thing I noticed is the DPM has what appears to be a serial port (as does my XP machine) - is that likely to work and would any RIP software settings need altered for serial? (this is unless it's just a port for programming).

Can the DPM be run with any other RIP software? Open to any suggestions.