lost all code

Hi All

i helped a friend out a couple of months back putting some vba code into her
access 2000 db to make it a bit flashier ... she went to use it the other
day and it didn't do the stuff i had programmed (e.g. populating a subform
from a combo box) .. she emailed it to me and when i had a look all the
"event procedure" comments where next to the events i had programmed but
there was no code at all in the database. We pulled a backup off the system
for 4 months ago but it has the same "problem". Could anyone shed any light
on how the code got "deleted" or disappeared or whatever. I've never seen
this before and i'm qiute concerned that if i regenerate it all its just
going to disappear again.

Cheers
JulieD