My first REAL SCARE with the Boxster! need some advice..

[first boxster]

I have had the same thing in my filter. I was told that is was the seal on the cam adjuster.Why do these fail? I am planning on doing the work plus the adjuster ramps and tensor this fall. Am I looking for problems doing this. Nothing else is showing in the filter.
I have a 2000 S with approximately 89,000 miles.