After an upgrade of SEF to 7.0 you are seeing incoming HTTP traffic being dropped and an error in the logs (switched to kernel proxy).
To work around this problem: Open the config.cf file with a text editor. Add the text string: httpd.tls_kernelproxy = 0 The string should be added to the bottom of the httpd controls: section of the config.cf file. Save the changes and close the file. Restart the firewall.
Adding this line to the config.cf file disables the Kernel Proxy. The reason for doing this is because SEF 7 uses a different way to pass HTTP traffic, by disabling the HTTPD Kernel Proxy you are just putting the passing of HTTP traffic back to the way Raptor 6x did it. Symantec has release a June patch that should fix this problem.