there is a drip tray under the machine, when it gets full it exhibits all the symptoms you describe.
Before i knew this i paid silly £'s for someone to send minutes faffing and curing the problem.
now i just get loads of towels out and tip the machine over to empty the tray (HASTEN TO ADD, PROBABLY NOT THE MANUFACTURERS RECOMMENDED METHOD, but it works for me, saving £'s)
bloke in Brum, September 2011