Clio III Rear Door won't open from inside

Intermittent problem with o/s rear door on 2006 Clio where door cannot be opened from inside (a bit like having the child lock lever set, but makes a slight clicking noise when operating the inside latch lever). As mentioned, problem is intermittent - often works fine just after unlocking with central locking key, but generally doesn't work after a journey (something rattling loose??).
Car is a low series 5-door with manual child locks on the rear doors.

If anyone has the answer or some...

Clio III Rear Door won't open from inside

* This article was originally published here