We had the same problem. After I changed the oil the first time, I put the cap on backward. Its not easy to see what is correct because it twists in place either way. After a day of commuting, the next morning there was so much oil on the engine and ground I was convinced something was plugging the breather tube and causing it to blow out the dipstick or cap or at some seal. I took it to the dealer and they added die and found no leaks and the pvc system was fine. Then after reading about the cap at this forum, I changed the cap 180 degrees and the problem never returned. Its been 15K miles since and after 25K total miles and 3 oil changes, this engine burns almost no oil and leaks none.
07 WK CRD Limited