Did you run Compact & Repair then try to zip file with Windows Compression? 2MB Zip file allowed.
When you change field names, means changing field name referenced in queries, forms, reports, code, expressions. Name change will carry through in queries that directly pull the field but nowhere else - such as VBA, calculated fields, ControlSource property.
There are 3rd-party tools that can help with search and replace. I used Rick Fisher's Find & Replace but it may no longer be available. Another is V-Tools. http://www.skrol29.com/us/vtools.php