Just had my oil service and they said that there was some oil coming from where the oil filter is, it could have not been on quite well enough or the oil filter gasket could need changing but i need to see if it continues for a few days and see what happens as its not a major leak!!
Also had a small leak from an oil line apparently underneath the turbo's that looks like it sweating and hence the leak, however again can be changed quite easily!
Dont know if this might be any of the problems you have but said i would let you know what happened!!!