Unable to queue from stdin-unknown

[Sue Toeppler]

We're running Cups 1.4.6.

We periodically receive this message when sending a print request to a network printer from a Cobol program "ERROR - unable to queue from stdin - Unknown".  The user tries again and it works ok.

This message in the error_log file appears to coincide with the error:

E [26/Aug/2011:07:42:09 -0500] Returning IPP client-error-bad-request for Send-Document (ipp://localhost:631/printers/Trailer1025) from local
host

Any ideas as to why this happens?