Partially Info sync problem both ways (phone to Mac and Mac to phone), running out of ideas.

Tried resetting isync history, unchecking "All Contacts" to Selected Groups and re-checking back and forth, reading tons of threads, no solution yet.

Wiping out database on my iphone is not an option: I just realized the bug today. I don't know since how long it's not syncing anymore, I will loose all the data I entered and modified on the phone since the sync broke.

Any tool/help to inspect the delta of the database on the phone and the Mac? (like "diff") ?

Phone is jailbroken.

Thanks for any hint!!!