[22:11:50] <gavinandresen> MT`AwAy: RE: curl and ssl: I bet you have: rpcssl=true in your bitcoin.conf
[22:12:26] <gavinandresen> (correct syntax is rcpssl=1, I made the command/option file parsing consistent in 0.3.18)
Indeed, replacing rpcssl=true to rpcssl=1 fixed the issue.
Someone should update GetBoolArg() to accept 'false', 'true', 'yes' and 'no'.