Had similar issues to this – Except using stock FedoraCore6 box and Mod_security2, Brayne’s (see above) fix worked, but you have to alter modsecurity_crs_30_http_policy.conf from
SecRule REQUEST_HEADERS:Content-Type “!(^$|^application/x-www-form-urlencoded|^multipart/form-data|^text/xml)”
to
SecRule REQUEST_HEADERS:Content-Type “!(?:^(?:application/x-www-form-urlencoded$|multipart/form-data;)|text/xml)”
Windy
