Why doesnt PDB allow me to view the current line?

[hardcoreUFO]

I have some code that I am trying to debug (Python 2.5.2 on OSX) using
pdb. However, when the code reaches the pdb.set_trace(), it does not
allow me to view the current line:

> /Users/chris/Research/ISEC/build/bdist.macosx-10.3-i386/egg/pyrl/reinforcement.py(943)__call__()
(Pdb) n
> /Users/chris/Research/ISEC/build/bdist.macosx-10.3-i386/egg/pyrl/reinforcement.py(946)__call__()
(Pdb) l
[EOF]
(Pdb) l
[EOF]

It steps through the code fine, but for some reason returns end-of-
file when I want to look at the code.