Hi there,
1) Check the <nimsoft>\robot\q1.rdb and q2.rdb files. These are the queue files for the spooler.
If q2.rdb is small (~1KB) and q1.rdb is continuing to grow, there's probably corrupt data in q2.rdb that's causing QoS to queue on the spooler.
2) Stop the robot.
3) Move q2.rdb to a temp folder
4) Restart the robot.
This will allow the robot to create a new q2.rdb file which should then allow q1.rdb to begin to flush. An analysis of the archived q2.rdb may show corrupt data via illegal characters which was disrupting the normal data flow.
If you don't mind loosing any data, you can simply delete both of those files and they will be recreated after the robot is re-activated.