Contact's categories problem

[luizcvm]

Hello

I'm developing a SyncML server with Funambol and using Synthesis AG for iPhone. When I set the CATEGORIES field in vCard to the mobile, the iPhone client associates that contact in groups that comes in CATEGORIES. But when I set the CATEGORY with empty value, the client keeps the associations of the contact instead of removing them.

Ex.

// send this first
CATEGORIES:group1,group2 -> it works and create the association of contact in these groups

// send this in another sync
CATEGORIES: -> nothing happens on mobile

// at last, send this
CATEGORIES:group1 -> it works and keeps the association of contact in group1 and remove the association in group2

Do anyone knows how to solve this?

Thanks