flame trap blocked/oil leak ....help !!!

Hi just purchased a 95 N 850 GLT estate 2.5 20v auto (UK) but i am having problems with oil leaking from the top of the engine and dripping onto the heat shield thus causing smoke n smell.

I have changed the oil cap seal but it makes no diff - i have read on here that unblocking the flame trap might help - can anyone tell me why this would cause an oil leak ?? I have also read that you can do away with the flame trap altogether ..is this true ??

Or could it be something else that is causing this annoying leak (as a temp measure i have put a small rag into the gap where the oil is dripping onto the exhaust heat sheild to stop the smoke n smell)

Help...please !!!