file created by gnumeric1.05 can't be open by 1.01

["Reuben D Budiardja" <reubendb goshen edu>]

Hi,
My colleagues and I have different versions of gnumeric. We all accessing the 
same file stored in our file server. We found out that a gnumeric file that 
was created by gnumeric 1.01 can be opened by gnumeric 1.05. After the person 
who use gnumeric 1.05 modify the file and save, another person who uses 
gnumeric 1.01 can't open it. It just gives the error message "Not a gnumeric 
workbook" (or something similar). 

The file was saved as a default gnumeric format. We use RedHat 7.2, and 
upgrade the gnumeric using rpm from RawHide in rpmfind. 

Is this behavior known/intended, or is this a bug? I don't think such a small 
different in version should cause something like this.

Thanks.
Reuben D. Budiardja