The fact that the unit does not keep time with DVB data stream and that you are prepared to accept this as a minor problem is, frankly, gob smacking.
What exactly do you expect us to do about it? Humax designed the box. It is their problem. They of course are not interested in fixing anything, like most manufacturers of stuff. You either take it or leave it (or install the custom firmware and an NTP client to keep it in sync.)
I admit that nothing in life is perfect, but this is a major fault, and both of you so called gurus are prepared to pass this off as working around deficiencies!!!