Can you print out your raw http request?
I've put up screen captures from Wireshark here:
http://imgur.com/a/Sh2jx#0Joulecoin:
Bitcoin:
I compared the code and the Joulecoin and Bitcoin code is exactly the same.
Try modifying the HTTPAuthorized function in file src/rpcserver.cpp at line 374 to print to the debug.log the passwords it is comparing:
bool HTTPAuthorized(map& mapHeaders)
{
string strAuth = mapHeaders["authorization"];
if (strAuth.substr(0,6) != "Basic ")
return false;
string strUserPass64 = strAuth.substr(6); boost::trim(strUserPass64);
string strUserPass = DecodeBase64(strUserPass64);
LogPrintf("1:%s 2:%s\n", strUserPass, strRPCUserColonPass); // ADD THIS LINE
return TimingResistantEqual(strUserPass, strRPCUserColonPass);
}