Harden BufferManagerReadStream underflow logic

submitter reports following exception as causing issue in production env:

-- Servers periodically fails to make IDL call with BufferUnderflow.
[Lclassmcs.interfaces.EventListenerPackage.EventData;@414f9513 org.omg.CORBA.COMM_FAILURE: ----------BEGIN server-side stack trace----------
org.omg.CORBA.COMM_FAILURE: vmcid: SUN minor code: 217 completed: No
              at com.sun.corba.se.impl.logging.ORBUtilSystemException.bufferReadManagerTimeout(ORBUtilSystemException.java:2661)
              at com.sun.corba.se.impl.logging.ORBUtilSystemException.bufferReadManagerTimeout(ORBUtilSystemException.java:2683)
              at com.sun.corba.se.impl.encoding.BufferManagerReadStream.underflow(BufferManagerReadStream.java:123)
              at com.sun.corba.se.impl.encoding.CDRInputStream_1_1.grow(CDRInputStream_1_1.java:93)
              at com.sun.corba.se.impl.encoding.CDRInputStream_1_0.read_octet_array(CDRInputStream_1_0.java:649)
              at com.sun.corba.se.impl.encoding.CDRInputStream.read_octet_array(CDRInputStream.java:195)
              at classmcs.interfaces.ByteListHelper.read(ByteListHelper.java:55)