I have recently notied that my engine hunts a bit just after i have started from cold and driven say a mile or 2 then get caught in traffic. Seems to do it more the 'second' start of the day, like when I am on my way home from work. As soon as it's warmed a bit more, or straight from cold it's fine.
I have recently serviced it including a new fuel, air and oil filter and fresh oil. Also cleaned up the air mass meter, and since then it's been running great except for this small issue.