status change workflow triggering twice on service.update

Hi,

1. We have a OOB workflow on an entity, it triggers on 'Record Status change'.

To Deactivate the record we are setting value in

status=1, statusreason=2 and calling  service.Update().

We found the record is Deactivated but the workflow triggering two times and in both times the record status showing as 'Inactive'.

Why it is calling 2 times? How can I prevent the 2nd time workflow calling?

2. One more thing I found in Audit History:#

It recorded 2 update events

latest:      Status                Active   InActive

               StatusReason    Active   InActive

   old        Status                Active   Active

                StatusReason    Active   Active

Even the record status is Active-->Active, why it showed me in audit as update?

Thanks

krishna