Thanks Barry -- the program in this example dies (by design) at the line
    a=b/8
(because b is undefined) and that's where I would expect pdtrack/python-mode to kick in.  But it doesn't.  Running from M-x pdb, I get,

Current directory is ~/test/                                                    
> /home/charles/test/main.py(1)<module>()                                       
-> from Cat import *                                                            
(Pdb) r                                                                         
meow                                                                            
--Return--                                                                      
> /home/charles/test/main.py(4)<module>()->None                                 
-> c.hello()                                                                    
(Pdb)          

...and the pdb window shows the arrow in the main.py file,                                                                                
c=Cat()                                                                         
=>hello()  

...rather than the arrow pointing in Cat.py : hello() where it ought to be.

I wonder if this is actually a pdb issue rather than pythonmode or pdbtrack, as I can't get pdb itself to print the code around the error line either,

Current directory is ~/test/                                                                       
> /home/charles/test/main.py(1)<module>()                                                          
-> from Cat import *                                                                               
(Pdb) r                                                                                            
meow                                                                                               
--Return--                                                                                         
> /home/charles/test/main.py(4)<module>()->None                                                    
-> c.hello()                                                                                       
(Pdb) l                                                                                            
  1     from Cat import *                                                                          
  2                                                                                                
  3     c=Cat()                                                                                    
  4  -> c.hello()                                                                                  
[EOF]                                                                                              
(Pdb) bt                                                                                           
  /usr/lib/python2.6/bdb.py(368)run()                                                              
-> exec cmd in globals, locals                                                                     
  <string>(1)<module>()->None                                                                      
> /home/charles/test/main.py(4)<module>()->None                                                    
-> c.hello()                                                                                       
(Pdb) d                                                                                            
*** Newest frame                                                                                   
(Pdb) u                                                                                            
> <string>(1)<module>()->None                                                                      
(Pdb) l                                                                                            
[EOF]                                                                                              
(Pdb) d                                                                                            
> /home/charles/test/main.py(4)<module>()->None                                                    
-> c.hello()                                                                                       
(Pdb) l                                                                                            
  1     from Cat import *                                                                          
  2                                                                                                
  3     c=Cat()                                                                                    
  4  -> c.hello()                                                                                  
[EOF]                                                                                              
-UUU:**-


Please note that I can manually step into the correct hello() function if I step through main from the start;  also if I put a breakpoint hello() then it works correctly,

class Cat():                                                                                       
    def hello(self):                                                                               
        pdb.set_trace()                                                                            
=>      print "meow"                                                                               
        a=b/8      

However the kind of code I'm debugging (large scale stochastic bayesian network models) tends to throw lots of errors like div by zeros at me at random times during the initial runs, so it's very annoying not to be able to jump straight to the error line, and have to manually stop and write a breakpoint for each one (that's what I'm doing now as a workaround but my debug cycle time is about 10x what it would be without the problem).

Please can you let me know if you can reproduce these errors, or let me know if you need any more information?   (If not, I'll try it on a clean install somewhere for you)

Charles