Mapped network drives don't display in Explorer

When I map a new network drive, it shows up in the drive tree, but on the right side in "My Computer" where it lists all the drives, it's not there. A new window opens showing the contents of the drive like it should. If I close explorer and open it agai
n, the network drive is gone completeley. If I go to disconnect network drive, the newly mapped drive is there. I cannot for the life of me figure out what is wrong. Is there a registry setting or profile setting that does this? If another user logs on
, the drive is visible???? Help please!!

I really need some help with this please!