How to set primary contact to false (uncheck)?

[TimSebel]

Hi,

I'm unable to uncheck the primary contact, set it to false through my application and I don't know what's the problem. I don't get any errors, it just stays checked.

This is what I've tried so far:

Primary_Contact__c = false,

Primary_Contact__cSpecified = false,

and 

Primary_Contact__c = null,

Primary_Contact__cSpecified = false,

or not to use these parameters at all during update but nothing works.

Any help would be appreciated.

All other properties are being updated properly.

Thank you

[SimonF · Accepted solution]

You have to set specified to true, so that the actual value is sent to the server.

[TimSebel]

Thank you, that is correct.