Item in transfer process for long

Experts,

I have a typical situation where in some of the carts have the status " Item in transfer process" they have been approved and showing the status approved .

I checked the Monitors and it reads. Spooler communication error " communication error transferring xxxxxxxxx item. Can you throw some light into how to deal with spooler communication errors, and what could the probable error.

Thanks a lot,

Manyam