If you were banned, then the ban was surely lifted after max 3 hours. If not, then there must be something else that prevents you to connect.
* Rebuilt URL to: http://stratum.nicehash.com:3333/
* Adding handle: conn: 0x7f994c013e80
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 1 (0x7f994c013e80) send_pipe: 1, recv_pipe: 0
* About to connect() to stratum.nicehash.com port 3333 (#1)
* Trying 91.223.115.35...
* TCP_NODELAY set
* Connected to stratum.nicehash.com (91.223.115.35) port 3333 (#1)
* Connection #1 to host stratum.nicehash.com left intact
[2014-06-18 10:43:23] > {"id": 1, "method": "mining.subscribe", "params": ["cudaminer/2014.02.28"]}
[2014-06-18 10:43:23] stratum_recv_line failed
[2014-06-18 10:43:23] ...retry after 15 seconds