Jeff and Rich, thanks for the replies. This is kind of an elementary question, but what exactly is the definition of "blowby"? I've seen the word used a lot, but haven't yet run across an explanation of what it is.
Jeff - Your explanation makes a lot of sense. I just changed out the air filter a couple of months ago (discovered lots of oil inside when I opened up the air cleaner), so maybe this is just something normal I'll have to clean up on a semi-regular basis.