I've only carried out the procedure on a couple of BC9500s, but no-one else has replied. For me, a new battery solved the problem - I think I had to carry out the COdE procedure again after battery replacement, but there have been no further problems since with either system. In my experience, if you keep the system connected to mains power the problem may not re-occur - my mother-in-law's system failed early because she switched it off at the wall every night.  However, if the battery is flat then it may be close to leaking, hence worth replacing. I'm currently debating changing the battery in a BS3000 that I have taken apart for door/CD belt changes - will probably do so to give it a longer lifespan.