Unable to start Spark Streaming Context

Hi,

while issuing the command to start Spark Streaming context, I am repeatedly getting following error on spark-shell

scala> ssc.start()
java.lang.IllegalStateException: StreamingContext has already been stopped
at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:632)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.(:32)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.(:37)

i did stop sc before creating streaming context .

Please help