asterisk users - Sep 2006 - ast_parse_allow_disallow: Cannot allow unknown format 'h264'

I see in CLI:

 ast_parse_allow_disallow: Cannot allow unknown format 'h264'

What can I do ?
I see on Asterisk home page, that h264 is not listed.
When does Asterisk need h264 at all? If one phone calls another phone, 
than it is only passed through and does not need it, or am I wrong here?

BTW, if I use SER, would this be solved?

bye

Ronald