Digital BW, The Print

I'm trying out the Quadtone RIP, current version, with an eMac 700 MHz 512mb
RAM, driving an Epson 1160. The eMac is running OSX 10.3.4. The eMac's
system is fine, and it prints to the 1160 OK via the Epson driver, as it
also does to a 1290s.

When ever I try printing via the RIP, it almost always fails after
displaying printing 4%, and with this error message

-536870163: unable to send print file to printer (cancelled 0)

Only twice has it printed a file OK, but in each case it would feed multiple
pages through before eventually printing. The last 10 - 15 times I've tried
it always fails as above. Once it sat for ever at 5% and no error message.

All the settings are OK. Has anyone seen this problem before or do they have
a solution to resolve it?

Steve Bell