Jobs stop processing on server install

PDF Creator eventually stops processing jobs.

I have a server install of PDF Creator 1.2.0 on Windows Server 2008 R2. A service runs the pdfcreator executable. Users print to pdfcreator via a network share. There are two print queues, one for jpg output and another for pdf output with the results autosaved to a directory on the server.

This works for a while but eventually jobs start stacking up in the PDFCreatorSpool directory with the .inf and .tmp files remaining.. If I run PDF Creator from a client logon in the foreground I see all of the waiting jobs and the client program immediately stops responding after displaying the list of jobs. It says the first job is "Printing" but nothing proceeds. There is nothing in the windows print queue. No errors show in the windows event log.

If I stop the service and run the client in the foreground then it still hangs.

I can see CPU activity on PDF Creator but it's still hung.

If stop pdf creator and delete the contents of the PDFCreatorSpool then it works for a while but will eventually hang again.

I have already tried uninstalling, deleting any remaining files, and then reinstalling pdf creator but the problem persists.

Any suggestions? Any way to turn on more detail in the error log?