Hiya Mate,
Are sure it is the Digiplex unit ? Cutting out and running on one cyclinder and then stopping? Leave it for 5 minutes and then re-starts ? Anyway, mine had similar problems. The usual cause is the soldering on the internal cicuit board goes brittle and fails. It is possible to remove the back and re-solder the dodgy areas. Also, the block connector is suspect as the wires and connections sometimes come adrift. It is cheaper to get another block connector and re-wire in to the new one.
Northwest Motorcycle Services are very useful and can be contacted on 01704 531616 or visit
CDI Unit - Honda, Yamaha, Suzuki, Ducati, Kawasaki, Voltage Regulator Rectifiers, Speed De-Restrictors, Alternators for motorcycles.
Hope this helps.