I have a Sony Ericsson P800 phone.
upon syncing with iSync I noticed that some contacts synced properly:

whereas others ended-up "empty" in AddressBook

The only common denominator I can find between the records that went wrong - is that they did not have any "Home" details - only "work" details.

I also noticed that the contact photos on the P800 are "downgraded" to the size that addressBook uses. Thus making them appear tiny on the phone:

The iSync Log appears to claim that contact groups were synchronised - but that does not appear to be true (I have totally different groups in phone and in AddressBook - the groups don't even have the same names.)

vs:

the log for my first (and major) sync is here: and here is the firmware for my P800: