oil fill cap/valve cover oil leak

i've got a 04 jetta, and pretty much since new, it has had a slow leak on the valve cover around the oil fill area. it seems as though some is coming from around the fill cap, but some also appears to be coming from where the fill cap base is attached to the valve cover. looking at the exploded view of the valve cover in the bentley manual, it doesn't appear that there is any kind of seal between where the fill cap base attaches to the valve cover. anyone know if there are any seals that can be replaced there?

btw: i have taken it to the dealer twice so far for this. both times i have explained that i do all the work, use a funnel, etc, and have not spilled any oil. both times they came back with "cleaned oil fill cap. tech must have spilled oil on last fill." it is this nice little game we like to play...

There is a seal on oil fill cap

is the CCV plugged?

i don't think the ccv is plugged, as this has happened since new...i'll double check next time i am under the hood, though.

is there also a seal/o-ring between the valve cover and the oil fill base? how does this come apart? there is no mention of it in the bentley...

thanks