File Name changes across Samba

[NoOp]

I've just found a rather odd issue with file names via Samba.

System 1 (Hardy) has a file saved from a gmane.org news server and the
file name is:

Formulas in Writer table - bug?.eml

System 2 (Intrepid) I open a samba share path to System 1 and view the
folder where the above file is located. Instead of the file name being
'Formulas in Writer table - bug?.eml' the file is instead showing as
'FYL228~4.EML'.
  So I copy the file from System 1 to System 2, and sure enough, the
file shows up on System 2 as 'FYL228~4.EML'. I copy that file back to
System 1 and it shows up on that system as 'FYL228~4.EML'.

Now I recognize that there are bound to be all sorts of issues with a
file named 'Formulas in Writer table - bug?.eml'. But found it
curious/odd that it would get changed to 'FYL228~4.EML' across samba.
I renamed the file elimiting the '?' to: 'Formulas in Writer table -
bug.eml' and now the file shows the same on both systems.

So here's the question: anyone know why the '?' in the file name would
cause samba to change to 'FYL228~4.EML'?