Sustaining Information

I maintain a project spreadsheet for our engineering group to list all projects that are being worked on each month. This sheet basically is just a long list with an autofilter on each column to sift between which engineer has a project and which manager or location the project is for. Other than the list being very long and a lot of information being present, there really is not anything difficult about the sheet.

My question is that I notice little quirks from time to time, with things like my autofilter moving rows as well as my freeze cells moving rows. My first thought is that this is a shared workbook, and not all users are on the same version of Excel. Two of us are using 2003, and the other 8 are using 97. Has anyone else come across issues like this? Is it a possibility that there is too much information for the filters to sustain their spots?

Attached is the sheet for reference, input would be valued. Thank you.