Hello,
Try these steps:
Check the Security Logs under Client Management for Denial of Service Detections for the printer's IP address to confirm the issue.
To resolve the issue you will need to disable Denial of Service detection within your Instrusion Prevention policy or you will need to add the printer's IP address in "Excluded Hosts."
To add the printer to "Excluded Hosts":
1. Open your Intrusion Prevention Policy.
2. Choose to Settings on the left.
3. Check the box for Enable excluded hosts and then click the Excluded Hosts... button.
4. Add the IP address of your printer and choose Okay.
Reference:
Denial of service detected on Network Printers
http://www.symantec.com/docs/TECH139213
Hope that helps!!