I'm a former 1080 owner and I know the unit pretty well. ON ocasion they are known to output a bit of hum but that normally has to do with odd grounding problems. CLicking is most likely caused by some kind of a mild power interruption as in oppose to software problem. But really, having no real background in electronics I can't say for sure.
Do give Roland a call since they might be the only ones with real answers.

-ED-