Starting London-Mumbai must have seemed like a good idea at the time, but the route is now saturated. BA have gone up to twice daily, VS are daily, Jet Airways are twice daily and Air India is still there. Plus all the airlines who can give connections at Gulf airports.
Surely, if BMI was travelling really well on the service, they could borrow a plane from a friend - perhaps a chance to see if A340s would fit into their network?