I've upgraded to Office XP / Outlook 2002 and now phone numbers are not synchronized when off-line.

Google

By default Office XP sets Outlook 2002 to NOT download all the full details for the global address list.  You must set your Outlook 2002 client to download the full details.  Then you must manually download the address list as the full list is generated once per day.

To set Outlook 2000 for Full Details.

Click Tools
Click Options
Click the Mail Setup tab
Click the Send/Recieve button.
Click the Edit button
Be sure that "Download Offline Address Book" is checked.
Click Address book settings.
Change the setting to "Full Details"
Make sure "Download changes since last synchronization" is UNCHECKED

Click Ok.

To manually download the address list:
C lick Tools
Click Send/Receive
Click "Download Address Book"

This should cause a full update of the address book.

If you find future synchs are slow you may want to go back into the settings in the first part and re-check the download changes since last send/receive.