Mine does too. He has since 5 months old. He is 2 now. It isn't teething -- he's had all his teeth for awhile now and it still happens. More than half the time he ends up with wheezing, ear infections, or pnemonia. But always starts as this every 5 week cold. I can predict them almos to the day.
I have no idea what it is. If anyone has any clue -- I'd love to know. I've sort of just settled on allergies. Seems he gets sicker in the winter months. And he has an obvious reaction to fresh cut grass or wet leaves.