vfs.file.exists problem with identical names except for case

[LenR]

It seems that I can't add both items:

vfs.file.exists[/opt/tivoli/tsm/client/ba/bin/EN_US/dsmc.hlp]
vfs.file.exists[/opt/tivoli/tsm/client/ba/bin/en_US/dsmc.hlp]

Where the only difference is the case of "en".

Message is: An item with the Key [vfs.file.exists[/opt/tivoli/tsm/client/ba/bin/en_US/dsmc.hlp]] already exists for host [Template_Linux]. The key must be unique.

Any thoughts?

Thanks