This works for BES. If you have the Desktop [SYNC] service book, it might work for BIS. Since you've waited 5 days and nobody else has responded, what do you have to lose by trying?
Options/Advanced Options/Service Books
Select the entry "Desktop [SYNC]"
Push the Menu button
Select Delete
Answer "yes" to the "are you sure question?"
Without turning off the blackberry, remove the battery
Leave the battery out for a minute or so
Put the battery back in
After the blackberry boots up, select Options/Advanced Options/Service Books
Push the Menu button
Select Undelete
The Wireless Sync option should now be present for Contacts, Tasks, Notes, Messages, and Calendar. I walked thru these steps with my properly functioning 8830 before I published them. The first time I undeleted, the service book came back, but the Wireless Sync option did not come back. I repeated the entire process and the second time the Wireless Sync capability was restored. So if you do it and it doesn't work, repeat the entire process before giving up.
Thanks for the follow-up. I've never had a BIS account, but I believe, based on your results, that what I posted is the BES equivalent. Since resending worked for you, I'm going to add BIS resend service books to my response in the future.