Whatever version of libCURL you linked against isn't redirecting to the correct URL. Use the correct URL in the arguments instead and it should work.
./rpcminer -url=http://mining.bitcoin.cz:8332/ -user=user.1 -pass=pass
I compiled with curl 7.21.2 and appended the "/" on the end of the url and got the same result, 0 khash/s