Maybe something like that. This is Number '09 version 2.3
Part of the issue may be you are using Numbers '09 version 2.3. I am using Numbers 5.3 (the year of release was long ago dropped from the name) and I suspect when Ira says, "I am using the current version of Numbers" he is using the same version I am. Numbers '09 is at least 8 or 9 years old and there have been a lot of changes, improvements and fixes over the years.
My suggestion would be to log onto iCloud and use
Cloud Numbers (essentially an on line duplicate of the current Numbers app on MacOS and iOS) and see if that does not solve your problem. IIRC you are on dialup, so that may not be an ideal solution, but at least it would tell you if the problem was in your data file or a limitation in Numbers '09.
