Kentico 7 Import Tool Kit, Publish option not working

Hi, We are trying to import and Publishing the data using Kentico 7 Import toolkit. It works well without Publishing the data but when we check the option to Publish while importing the data on import step 2 (Automatically Publish documents under workflow) It give us the following error,

"An error occured on import: [WorkflowManager.GetCurrentStepInternal]: Given node is exclusively checked out by another user."

We already checked in All the Node/Items in Kentico CmsDesk interface But still getting the same problem.

Thank you Arshad