Oil Filter Cover Gasket Leak

As topic, I changed the oil today and there is a slight weep from the cover ?, bolts are tight enough and I don't want to over tighten them, question is does the gasket fail ?, not seen anyone post on here with similar problem but maybe someone can advise ?...cheap to replace 11335-MBN-670 £4 from dealership for the rubber   

I have heard of this before , if you look in the service manual it tells you to replace the rubber gasket for the cover for a new one everytime you change oil , that is a little bit excessive as i am still using  my original seal , but if it starts leaking get a new one simple and cheap to do . 

Grease the O-ring and re-assemble, that should stop it.

Unless the O-ring has been damaged upon installation..

Seems to have stopped itself....will keep an eye on it