Sometimes when timer service is not able to start the time job  for content  
deployment, this might happen.

You can try following action:

1. Restart Timer Service through Service.msc on source farm.

If the operation times out then increase timeout for windows services as
follows:

Regedit
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control.

String Value: WaitToKillServiceTimeout
Value Data: 60000

Create DWORD value at same location:

DWORD Value: ServicePipeTimeout
Value Data: 60000

2. Clear configuration cache as per instruction mentioned in KB 939308
(Error message mentioned in this KB is different but the resolution section
applies here )

3. Delete the Content deployment  Path and Job in question and recreate them.

4. You can see if this is becasue of timer job or not. Just run STSADM
export of the source site.