links don't update when excel files are copied

hi,

I have a folder called 'X' on my network containing 3 sub folders with excel files. Some of the excel files contain links to other excel files within the 3 subfolders. There are no links to any files outside of 'X'.
My problem occurs when I copy folder 'X' and its 3 subfolders to a PC or another network. Once the folders are copied, I open an excel file as normal and it asks me if I want to update the links. I select yes.
It then tells me it cannot find some of the linked files and I have to browse and select them manually. These so called 'missing links' are actually in the same place they always been within the subfolders. Only the location of folder 'X' changes. e.g. '\\networkcomputer\excel\x' is copied to '\\mycomputer\x'.
9 out of 10 links update automatically but there is always one of two which still point to '\\networkcomputer\excel\x' instead of '\\mycomputer\x' after folder 'X' has been copied.
Is this a problem anyone has come across before or is it a hidden excel bug??? Any assistence would be greatly appreciated...

del