Error Message on Closing

Does anyone know what this message means and if so is there anything that
can be done to correct it.

Almost each time I close Outlook 2003 in Windows XP SP3 I get an error
message Unexpected Memory Leak.

" An unexpected memory leak has occured. The unexpected small block leaks
are:
13-20 bytes: TObjectList x 2, Unknown x2"

Any suggestions would certainly be appreciated.
Thank you in advance for your support.

HankL