on-line tutorial bugs

[Ken Laberteaux <klaberte@nd.edu>]

I am trying to use the on-line tutorial at

http://www-aml.cs.umass.edu/~ns/index.html

However, the only way this seems to work is if I start on the first
slide and then go with continuous play.  If I try to stop and restart, 
I get the RealPlayer error:

--------
Connection to server has been lost.  You may be experiencing network
problems

pnm://www-aml.cs.umass.edu/courseware/ns/session1.ra?"start=0:13:57.8"
---------

Same happens if I use the arrows to move to a specific slide and then
hit either Continuous play or Play this slide.

Thus the only apparent option is to do the entire thing in one sitting. 
This is unrealistic if the session lasts several hours (which is what is
advertised at the beginning of the talk).

Is this a known problem?  Are there any work-arounds?

Much thanks,

Ken