Database Import Utility does not connect to the database and stops (4316298)

When connected to the database using TOAD, I try to import data using the Database Import Utility. I get the following error when executing:

IMP-00058:
ORACLE error 12154 encountered
ORA-12154: TNS:could not resolve the connect identifier specified
IMP-00000: Import terminated unsuccessfully

Passwords with the '@' symbol will cause the Database Import Utility to fail.

WORKAROUND:
Change the user's password to one without the '@' symbol and try the Database Import Utility again.

STATUS:
Waiting for fix  in a future release of Toad for Oracle.