Excel 2013 wrong validation on file from Excel 2007

Hi,

I have an excel file which have a data validation based on a list with source:

=INDIRECT(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(C2," ","_"),CHAR(47),"_"),CHAR(38),"_"),"-","_"))

But when I open the EXACT SAME FILE, the same validation have a different source:

=INDIRECT(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(F3," ","_"),CHAR(47),"_"),CHAR(38),"_"),"-","_"))

It would seem that Excel 2013 is changing the validation source for no reason. Does any one have had this problem? how did you solve it?

Thanks and regards