What you've encountered is normal. Here is what is happening.
When you send a print job to a printer, data is processed until one of two things occurs: and end-of-transmission (Control-D) character transmitted in the print job is reached (normal), or there is a timeout on the communications channel (typically abnormal). The Printer Access Protocol sets up, maintains, and closes connections between workstations, printers, and print spoolers.
When you cancel a print job using the print monitor, the PAP client on the workstation issues a PAPClose call and an ATP transaction request is sent to the other end with PAP function CloseConn. At the server/printer end, the receipt of the CloseConn causes the connection to be torn down--but the server/ printer may continue to process data for the ongoing job. When the PostScript interpreter is ready to receive more of the print job data from the client, it detects the PAP connection is closed and invokes the WaitTimeout timer, the default of which for Apple LaserWriters is 300 seconds (5 minutes). (This timer is also set to 300 seconds, for the current job, by the LaserWriter 7.x driver when it begins the print job). The LaserWriter simply waits until "timeout" and then assumes that the job is complete. At that point, it resets itself to the initial job state.
During some periods during the processing of a printing job, you may be able to cancel the print job almost immediately, but as you have found, other times when the printer is busy processing the job, it may take awhile before it even learns the connection was closed, and then another 5 minutes before it is willing to accept another print job. A faster printer than the LaserWriter IINT may require less time to process a job; therefore, a faster printer will enter the WaitTimeout period faster.
There are two workarounds to this problem. You may either:
1) Cancel the print job sooner
or
2) Don't cancel the print job at all
Alternatively, by using a faster printer, your printer will free up more rapidly after a print job is canceled.
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