Vista + 2003 Office =?

Recently faced with a unique case. Our employee has Vista on his computer, and he uses office 2003 (he did not switch to 2007). Network Novell-ovsky. So, if you open a .xls file from the network ( previously created in Win XP ) on this computer, the file collapses and does not open anymore (at the same time, it increases in size every 15). It happens with every excel file. Checked on another computer (put Vista and 2003 office) - the same thing.
Gee :)