Sep 15 11:51:04 2011-09-15 15: 52:27,228 SCSP.INTERNODE DEBUG: InterSCSP lost connection to 10.15.68.25:80
These are normal. Nodes pool a finite number of connections so as new node connections are needed, other idle connections are dropped from the pool. The other side of that connection does not know why the connection was dropped and logs a debug that the connection went away. If the connection had been in use when dropped, a higher level message would have been logged.