jdb cores with Internal exception, communication channel closed on breakpoint

This looks really broken. I've seen some cases where jdb works, but it
seems to do this more often than not...

hagen@mile[91]: jdb testam
Initializing jdb...
0xee312508:class(testam)
> stop at testam:6
Breakpoint set at testam:6
> run
run testam
running ...

The communications channel closed.
Internal exception: java.io.EOFException
at java.io.DataInputStream.readUnsignedShort(DataInputStream.java)
at java.io.DataInputStream.readUTF(DataInputStream.java)
at java.io.DataInputStream.readUTF(DataInputStream.java)
at sun.tools.debug.RemoteAgent.getThreadName(RemoteAgent.java:616)
at sun.tools.debug.RemoteThread.getName(RemoteThread.java:42)
at sun.tools.ttydebug.TTY.printPrompt(TTY.java:67)
at sun.tools.ttydebug.TTY.<init>(TTY.java:1341)
at sun.tools.ttydebug.TTY.main(TTY.java:1433)
hagen@mile[92]:


public class testam
{
  public static void main(String args[])
  {
    System.out.println("One line");
    System.out.println("Two lines");
    System.out.println("Three lines ");
  }
}

I think there's a similar report lurking in the database, but I couldn't find it.