Problems renaming files from a Win98 client

[Thomas ALtmeyer]

I have made some strange experience while trying to rename files under win98 and samba 2.07 running on a linux Server. 

The first time i create a File, i can freely choose the name in a mixture of upper- and lowercases, by example This Is A Test.txt.
If i Try now to change the name in the Windows Explorer to tHis is a TeSt.txt the case of the letters remain like original.
If i change the name to something completely different like What a Bullshit.txt, it works, but in neither this name nor in the original, if i rename back to it, i can change the case of the letters. What works is renaming the file to all upper or all lowercases, but if i do so, no more mixed upper/lowercase letters will work.

Anyone knows help?

Tom