Outlook 2000 DELETES !!! incoming email when reply

[Booba]

At some point recently, when I use "reply" to send message
back to someone I know, once message is sent, the original
message is nowhere to find, it is permanently deleted.

What is going on? HELP

The reply I already received (but it didn't help):
=========================
Go to the Tool menu and then to the Rules wizard and see
if you do not have and rule for that.
you can allsow go to Tolls option and look there as well
==========================
My reply to the above:
=========================
..... No such a rule (and
I didn't set one). In tools-options there was something I
unchecked (smth like "delete from inbox, when reply for
appointments"), but it didn't help. Original message is
still gets lost when I hit reply.
I am using Yahoo mail and those incoming
messages (that are gone from outlook) are still there and
not deleted, but I can't get
them back into Outlook even if I change the message to
as "unread" via direct login into my yahoo mail account
via internet browser.
===========================

HELP??????????????

 

[Guest]

Addition:
I also checked my view filter it is on "off" In View I
have filter on off. I tried to set it on and off just to
see how this works (It does). Also, If it was vew problem,
I wouldn't see the arrived message on the first place, but
I do. It only disapeares when I use reply function, the
original message is gone the moment I hit send (even if
the my reply/outcoming message is still in the outbox
folder).
I also run freshly updated Norton antivirus - nothing found

 

[Booba]

Cancel all that!!!! I got it !!!!
This is called "stoopid me": Here is what it was:

I apparently (must be by accident!) clicked on "sort
messages by icon" icon, then once any message is replied
to, it has a little arrow on it, therefore gets sorted to
the bottom of the inbox. So, nothing has gotten deleted...

Dahhhhh!!!!