Well the early days of any engine type are usually filled with problems. I seem to remember P&Ws grounding rather a lot of 747s for rather a long time- I bet their engineers were scurrying all over the place trying to repair an engine that should never have been let loose on the public in the first place. But they get fixed and burble away merrily for years. You seem to have a thing about RR engines- I like them. After shutting down many P&Ws on the 747-100, the RB211 was like a breath of fresh air. If you can only dredge up 20 year old bad stories, wake up and look around.....they are selling very successfully on the latest equipment.