Cannot close pst file from Outlook

[CrashDavis]

I have a couple of pst files connected to my Outlook XP profile, that I can't
disconnect. When I try to close by right clicking I get the The window "The
operation failed. An object cannot be found." They are not in the list when I
go to the Outlook Data files window under Mail setup in Control panel. If I
install them, they are listed twice in the mail folders window and neither
can be disconnected. If I go back to data file window and remove, only one
file listing is gone in the mail folders window. I do have full access to the
pst file. and they are the new XP format.

Thanks for any help!