Drag and drop invoking http get instead of post

[mambo_jumbo]

Has anyone have the same problem? cannot find a solution.
I have RESTdatasource with operation binding as in docs.

operationBindings:[
                   {operationType:"fetch", dataProtocol:"getParams"},
                   {operationType:"add", dataProtocol:"postParams"},
                   {operationType:"remove", dataProtocol:"getParams", requestProperties:{httpMethod:"DELETE"}},
                   {operationType:"update", dataProtocol:"postParams", requestProperties:{httpMethod:"PUT"}}
                 ]

listgrid is bound to this datasource but when i drop records on that listgrid http get methos is firing instead of post. Is there any method I need to everride, cannot find it in the docs?
Thanks