normal. especially after a "short" drive. oil sits in the chamber is is burnt off when started.
if it looks like a james bond car every time you start or while driving, then it could be the AOS. do the oil cap test as pin suggested.
mike focke has a good write up (where the image above came from) located on his web site:
http://sites.google.com/site/mikefocke2/airoilseparatorreplacement