Reference to values disappear after closing file
 

When I use this formula in a worksheet:

=INDIRECT(ADDRESS(COLUMN()+5,4,,,"C:\Temp\[januari_2010.XLS]sheet1"))

The values disappear after closing the file januari_2010.xls and the
error #REF! appears.
Apparently this formula can't keep the reference when the file is closed

But when I use this formula in a worksheet:

='C:\Temp\[januari_2010.XLS]sheet1'!$C$10

the value stay visible even after closing the file januari_2010.xls. How
is that possible?