why are my links not updating
 

I have number of links through a number of spreadsheets that are interlocked
and also reading from some medium size database style Excel workbooks, as the
linking is quite complicated I have had to check and re-check them, now
suddenly after it working fine, I am having a number of issues updating, when
I check the links within excel it tells me they are ok, even if a workbook is
open, still only gives me "ok", which used to read as "file open". this is
giving random results, if I go to another workstation and test this it then
again gives me another result. I have full permission on the network drive
and everything is set to update, none of the F9 functions seem to be working
on any stations and I have not scripted anything to stop this.
Am I going Crazy(well it's driving me nuts) or is there a bug that I need to
be working around, any file size or compatibility issues?
Am saving in xls and xlsx formats as we need certain lesser features to be
available for office 2003. The largest Excel file is about 65Mb, but all the
others are less than 5Mb.
This has all been working and now not updating.
Thanks in Advance