The issue may be due to any of the following
1.This is an FTP/URL message. This message is logged when you use the allow option of the filter command, and the Websense server(s) are not responding. The PIX Firewall allows all web requests to continue without filtering while the server(s) are not available.
2.This is an FTP/URL message. The Websense server is unavailable for access, and the PIX Firewall attempts to either try to access the same server if it is the only server installed, or another server if there is more than one.