[ic] userdb Oddity

[Orko]

I'm trying to understand why the following situation is happening:

1) user logs into our site and fills out an order form with name, phone
   number, etc.  Their data is saved into the userdb correctly by using
   a [userdb save] on the receipt.
2) user calls us and says that they mispelled their email address, and
   would like us to change it
3) I go into the userdb (MySQL) and change his email address to the
   correct spelling, verifying that it is correct afterwards with a
   lookup of his correct and non-correct email addresses.  The correct
   one is there, the non-correct one is not.
4) The user goes back into the site, and their email address that is
   displayed to them after they log in is the non-correct spelling... He
   calls back, so I check the userdb, and their email address has
   changed back to the old spelling!  The correct one is not present
   anymore...

Now, I have tested this out for myself, closing all browsers and
clearing all cookies before doing step 4.  This is totally reproducable
in our cart, with any of the user data in the userdb (not just their
email, but name, phone, etc)  I know it isn't something freaky the user
is doing, or a specific browser issue that is causing this to happen.

The only thing that I know of that would hold onto the old user data
would be the session data on the server itself.  We have this set to
expire every 30 minutes, and I haven't tested waiting 30 minutes between
step 3 and 4 yet.  This just seems odd to me that I can't change the
values in the MySQL DB and have it "stick" when they come back in.

Is there anything that I must do to correctly change a user's
information "on-the-fly"?  Is there another way to edit their
information, so that I can tell users like this that their information
has been changed, and I won't have to worry about it coming back from
the dead?

Thanks in advance,

-- orko