We have been experiencing the same type of thing. The best I can determine
through a little reseach on the microsoft knowledge base is that perhaps the
person who originally opened the file, temporarily lost their network
connection unbeknownst to them. During this time, the other user opened the
file and the network no longer recognized that the original user was in file.
At some point the original users connection was re-established and now both
users think the have the "live" version.

I will say I'm not sure this is the case and I don't totally understand
everything that I just wrote, but maybe it will help you.

"John" wrote:

Good morning,

We have a strange problem here with Excel2003, person A opens a document and
person B opens the same document without any warning about ''read only'' or
something like that.

Anothetr example is that person A opens a document and person B opens the
same document, person B gets a warning about the document is opened by
person A and person A gets a warning about ''sharing violence'' and was
forced to save the document under another name.

What is going on here?
The documents are saved on a Novell (version 6) disc, Excel is version 2003
and up-to-date with all patches.

Thanks.

John