Help with critical warning

I'm seeing lots of critical warnings on my administrator console. They're all basically the same but are appearing for two different clients:

Code:

Column Name	Value
Firewall Id	Firewall 427
Client Name	(client name)
Computer Name	(computer name)
MAC Address	(mac address)
Primary Server	(my server)
Date Received	2009-04-21 14:35:18
Date Occurred	2009-04-21 14:29:41
Level	Critical Warning
Event	Unknown code 00050007
Source	(my server IP address)
Target	(client IP address)
Protocol	ICMP
Rule	
Application	
User	

One of the clients is using XP Pro and one is Vista business. They're all using ESS4 business 4.0.417.

Any ideas what this could be?

 

This could be an issue with updating the definition files. Follow the instructions in the knowledgebase article located below to see if this fixes the problem.

http://kb.eset.com/esetkb/index?page=content&id=SOLN2134