HELP!! Network drive mapping issue.

I have recently encountered a Network drive mapping problem. Here is the scenario; a workgroup of 7 XP pro work stations with simple file sharing enabled and 1 file server (win2k3 standard just a file server). Friday the mapped drives on the workstations stopped reconnecting on login. I disconnected the mapped drives and remapped them using a different account with the same problem (I have to right click to open and then login or open and login from windows explorer). Also when i double click the the mapped drive (which happens to be a system drive C the "Select which program to open with" window opens and when I right click the mapped drive in my computer Autoplay shows up is this normal. I did not set up the shares or mapped drives but I do know the drives connected automatically before friday.