RTF mail - Outlook removes non-latin characters from attachments when dragged to filesystem

Dear Techies,

We're using O2K10 SP1 on W2K8 R2 SP1 Terminal Servers as well as O2K3 SP3 on W2K3 SP2 Terminal Servers. Mailboxes are hosted on E2K7 and Outlook is used in online-mode. Fileservices are hosted on EMC-storage.

Users approached me with a very strange encounter.

1. A user receives a rich-text mail
2. The mail contains one or more attachments (no matter what filetype)
3. The filename of the attachment contains Chinese characters

When users drag&drop these attachments to the filesystem, all Chinese characters are removed from the filename and only the latin characters remain (if any). If there are no latin characters in the filename then only a dot and the filetype remain (e.g. ".doc" or ".xls" or ".msg"). If there are two attachments of the same filetype, both without latin characters, then the first would be moved and the explorer crashes at the second one.
Drag&drop works fine for HTML-mails and plain-text mails, only RTF shows that strange behaviour. Using the function "Save all attachments" works properly for all mail-formats but this is time-consuming and our users need the drag&drop function for our document-mgmt system.

I played around a bit and found that it works for RTF as soon as I set the system-locale to Chinese. This is no solution for us as we have users and applications from across the globe that would struggle
with the Chinese locales.

To me it pretty much likes like a bug, especially since it generally works fine for HTML and plain-text mails and only fails for RTF-mails. On the other hand the problem can also be found in O2K3 which is almost 10 years old and it's hard to imagine that nobody had this problem before me in 10 years.

Thanks for your advice
Uli