James,
From Cisco IOS System Messages, Volume 2 of 2 :
Error Message
%VPN_HW-1-ERROR : slot: [dec] - [chars]
Explanation
An error occurred in the application that is using VPN hardware.
Recommended Action
Copy the error message exactly as it appears on the console or in the system log, contact your Cisco technical support representative, and provide the representative with the gathered information.
More on the on the IOS System Messages can be found here:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_system_message_guide_chapter09186a00801c843a.html
Hope this helps,
Jay