I built the following formula as instructed in the Help.
=DSUM(BUD2006.XLS!ACTUAL,23,$A$9:$B12)

When I close the BUD2006 file, the formula changes to the following:
=DSUM('D:\work\BUD2006.XLS'!ACTUAL,23,$A$9:$B12)
The formula appears to produce a value, up to this point.

When I copy this new formula to other rows, both the copies and the original
generate a #VALUE! error.

I assume it has something to do with the reference to the other file and/or
named range. Can someone help point me in the right direction?

Thanks.