Problems with Filters

[lok1gt]

Semi-new poster here.
Microsoft Office 2000

Using filtered columns for data collection. The sheet has been working properly for two years. User simplifies log by filterring and changing print area.
Now filters don't work.
When selecting the filter tabs in each column, the only options available are ALL, TOP 10 and CUSTOM.
Or...
When selecting the filter tabs in each column, all options are available, but when applied, it filters only a portion of the sheet and the remaining portion is unfiltered.

20 different people use this log every day, so it's impossible to see who did what changes to cause this.
I've tried putting all of the settings back to normal and it makes no difference. I've tried recreating the file from scratch and copy/pasting rows, but it carries the problem with it. I've also tried changing the formats of every cell to be identical and no matter. There are no formulas used and the only cell formatting are for general text or dates, color, and border.

Any help would be apreciated. Otherwise i have to manually type in every piece of information in these logs and that would take me two days.
Thanks in advance.