Try the following: Tools /Options / Calculations / Save external link values
- take the tick out and press OK. It worked for me.

"J Shrimps, Jr." wrote:

Have several spreadsheets with many links
to other spreadsheets.
When I try to save the spreadsheet
I get
"Not enough memory"
and then
"Unable to save external link values",
even though the links are saved
and the values are updated when
I re-open the spreadsheet.
Is there any way to avoid this?