ode45 gives solution in the "Dark Side," but not in Octave

[John B. Thoo]

Hi.  I have a question about using ode45 in Octave 3.2.2 (and OdePkg  
on Mac OS X 10.4.11) vs. in the "Dark Side" 7.4.0 (R2007a) (on a  
server ... Linux?).  My code can be found here at the moment:

<http://ms.yccd.edu/~jb2/PickUp/twoway.zip>

"run_twoway.m" executes the code.

Both Octave and the Dark Side solve the problem (i.e., do not return  
an error) to produce a solution  u,  and both give

> size (u)
ans =

   8192    102

However, while I can plot the solution in the Dark Side, in Octave I  
can plot only the first four frames.  In fact, in Octave I get  NaN +  
0.00000i  from  u(:,5)  on.  Why is that?

I would appreciate any hints.  Thanks.

---John.