Hi, This is a carry over from the wrong group(boost build). In short the "+ +" sequence is invalid in boost::regex and valid in PRCE via an addition made to Perl 5.10. So, I am porting regular expressions that are used in PRCE and having trouble getting around this limitation in boost::regex. snip1: const boost::regex regex_username_password( "(" "(?:" "[a-zA-Z0-9_.!~*'()&=+$,;?/-]++" "|" "%[0-9a-fA-F]{2}" ")+" ")" "(?:" ":" "(" "(?:" "[a-zA-Z0-9_.!~*'()&=+$,-]++" "|" "%[0-9a-fA-F]{2}" ")*" ")" ")?" "@" ); snip2: const boost::regex regex_url_params("\\s*;([^?>]++)"); Help! -s7