Make sure you are sending the proper data to the printer. If you send PCL emulation or text data to a queue that only accepts PostScript data, the job leaves the queue but does not print. Try printing to another queue, or see an administrator for other printing options.
The print job is probably in the buffer of the print server or printer. As soon as the printer is available, the job prints.
Make sure you are sending print jobs to the correct printer virtual device.
Verify the properties of the virtual device to make sure the print job is going to the correct printer.
Make sure the printer is working properly.