Excel 2007 program has errors when run on Excel 2010

I have an Excel program that I wrote on Excel 2007. The workbook has 88 sheets with formulas that cross reference sheets, data validation, form controls and a few macros.
It has been tested on many 2007 machines with no problems.
I have recently upgraded one of my computers to Excel 2010. It opened and ran the program in question, without a hitch. The problems started after I saved the program in Excel 2010.
The first problem was when I re-opened the 2010 saved version in Excel 2010, I got the following: ‘Excel found unreadable content in ‘File Name.xlsm’ Do you want to recover the contents of this workbook?’
After clicking ‘Yes’ a window entitled ‘Repairs to ‘File Name.xlsm’ appeared with the following lines:
Removed Records: Object from /xl/printerSettings/printerSettings4.bin part (Print options)
/xl/printerSettings/printerSettings12.bin part (Print options)
/xl/printerSettings/printerSettings20.bin part (Print options)
and so on up to 84.

The program appears to run fine after the repairs are completed.

The second problem was that Excel 2007 was then unable to open the 2010 saved version. I got the following: ‘Excel found unreadable content in ‘File Name.xlsm’ Do you want to recover the contents of this workbook?’
After clicking ‘Yes’ Excel has a number of attempts to recover the program and then the following appears: ‘The workbook cannot be opened or repaired by Microsoft Excel because it is corrupt’

I have tested the program on a second machine running Excel 2010, with the same results. I have cleared the xlstart folder in users/username/appdata/roaming/Microsoft/excel. I’ve also renamed the file as a .zip, then opened and removed all the files in the ‘xl/printersettings’ folder, but neither action has helped.

Any assistance would be greatly appreciated.