Excel file loosing controls if saved in 2010 and opened in 2003 or 2007.

[Mchael E]

I have spreadsheet that created with Excel 2003 some time ago and has worked for quite a while.

However sometime recently it has become corrupt and if I open it in an older version of excel such as 2003 or 2007 I get a loss of data error and it comes up without any controls.

Attached I have a copy of this file, but everything else but the controls removed. The controls work fine in 2010 or later but with not load in 2003 or 2007.

This does not happen to all sheets, but more and more cannot be used in old versions without me making any major changes.

Update: I tried the file in Excel 2016 and it could open the file fine, but the newly saved file still cannot be read properly in older versions.

Update 2: I created a basic file in 2003 with the same forms and they way they are supposed to look. The biggest difference is that the clean file is only 16 KB while the corrupt one is 602 KB. What is adding the extra size and how can I clean it up.

[#2]

I seem to have found a workaround. I converted the file to xlsx and then saved again as xls. Both files then worked in 2003 and 2007 and the xls became 450 KB. Still much bigger than the clean 2003 version but smaller than the corrupt version.

I would still like to know the actual cause of the corruption and hopefully prevent it in the future.