Problema with saving Office documents on network share

I have a Windows 98 SE notebook in a TCP/IP LAN with Windows 2003 server.
I have a strange problem in managing Office documents when they stay on a
network share (it doesn't matter if they stay on Windows 2003 server or
shared folder of other Windows 98 or 2000 or XP client).

I could not:

copy a Office Document to the network share
rename a Office Document on a network share
create a Office Document on a network share
save a modified Office Document on a network share

The error is like

Disk is full or insufficient memory.

I could make all the tasks above on a non Office Docuuments

Any Help ?

Sergio