I'm going to say this again....

One of the issues I have with your questions here is that you often don't do what's suggested and go off on your own, doing things that circle back to earlier suggestions.

So, again to repeat what Viv and I have both said...

Check what is being sent over the wire. If the json isn't being created, you'll get nulls sent to the controller.



>>Rather than guessing why not just fire up Fiddler (or similar) and see what's actually going over the wire. If you are getting padding then debug in the browser.....
>
>I am using FireBug.
>
>But the update statement being send to SQL Server makes no sense. This is what I see:
>
>

>exec sp_executesql N'update [dbo].[Clients]
>set [client_no] = @0, [client_name] = @1, 
>[Address] = @2, [Contact1] = null, [C1_Email] = null, 
>[C1_Phone] = null, [C1_Ext] = null, [Contact2] = null, [C2_Email] = null, [C2_Phone] = null, [C2_Ext] = @3, [EnteredBy] = null, [ModifiedBy] = null, [EnteredOn] = @4, [ModifiedOn] = @5
>where ([ClientId] = @6)
>',N'@0 smallint,@1 varchar(30),@2 varchar(max) ,@3 varchar(max) ,@4 datetime2(7),@5 datetime2(7),@6 int',@0=1002,@1='Ab Spare',@2='aa',@3='searchClientNo=',@4='0001-01-01 00:00:00',@5='2013-04-03 12:34:03.5351131',@6=240