Active sync of any flavor does not sync public folder in exchange 5.5/2000/2003. For that you need a 3rd party plug in.
The most reliable one is Intellisync's Handheld available at
www.sync.com
It allows syncing of both personal and public folders at the same time. They can combine on your handheld yet remain seperate at the desktop lvl. The only caveat is that it doesn't work wirelessly. You have to dock for the public folders. Very reliable program.
We have a client that we deployed a crapload of xv6700's to to replace a crapload of blackberries. (Blackberries have a version of the intellisync sw that come with them to sync the public folders)
At this client, email, tasks, files, etc are all synced wirelessly, but for their 2 public calendars and public contact list, those are updated when they dock at the office. Again, very reliable and they stay seperate at the desktop level.