Hi,
I find a problem when I try to search the header "Expires" with value 0.

At my kamailio.cfg the configuration is:
if ( search_hf("Expires", ":0@", "a") )
{                          
 xlog("L_INFO", "Encontrado expires 0 ($rm)");
}

I test with 0 (no wildcards regular expression), but this make matches in any Register with header Expires content 0. Example:
...
if ( search_hf("Expires", "0", "a") )
....

I saw some people control  expires=0 at contact header, but not my case. Example:
if (search("expires=0"))
{
   xlog("L_INFO", "Encontrado expires 0 ($rm)");
}