The icons in attachment files change

[KT]

I've got Outlook 2000 - When attaching a file to an email,
for example, an Excel file, the icon for the file changes
to one completely off base - like a solitaire icon, or
something else bizarre. Recipients even see the incorrect
icon and are skeptical of opening the file - even though
the file extension is still correct.

This problem occurs intermittently, on all file types at
that particular time. This just doesn't look so good on
those critical business related emails...

Any help greatly appreciated!
Thanks!
KT