I've just installed Python2.7 and pre-compiled PyMol 1.6 on my WindowsXP by following the instruction at PyMol wiki. 

The installation went through, and most function on viewing/drawing a molecule are fine except that "show as lines" doesn't work. When clicking "show as lines" or typing the command "show lines, all", nothing is on the screen, but when clicking/typing "show as cartoon" or other representation styles, it looks working well.

Can you please shed me a light if you happen to know the solution?