I looked in to this when syncing with outlook, and I think you can only have your main calendar sync.
Any additional ones will not sync.
The Help Centre (
http://www.google.com/support/calendar/bin/answer.py?
answer=98565) states:
"Google Calendar Sync will only sync events from
your primary Google Calendar and your default Microsoft Outlook
calendar at this time. If you've scheduled events on a secondary
calendar in Google Calendar that you'd like to sync with your
Microsoft Outlook Calendar, you can either move the event to your
primary calendar or export your entire secondary calendar and import
the events to your primary calendar."