Have you changed your crankcase filter?. If it is running on it must be getting another source of fuel eg: sump oil. if you havn't changed the crankcase filter it will be presurising the crankcase and forcing oil past your turbo seals.
strange, never re fitted my cover after taking it off the first time. dont think many peeps who do their own servicing refit theirs either. never heard of any leaks