I have confirmed this issue with versions 109, 125, and the current version as 
of 12/30/05.  The problem is that the autofilter result list does not update 
upon filtering like Excel does.  To demonstrate, run the autofilter and click 
the combo box for column 1 and select a filter criteria.  Now, click on the 
combo box for column 2 to further filter this list.  Now, if we were using 
Excel, the list of options would be limited to what remains in the filtered 
portion, not the entire list which is unfortunately what Calc does.  For small 
spreadsheets this is not a problem.  But when working with a large spreadsheet 
and you want to see what options for column B remain after filtering by columns 
A (in which case you would only need to look at what entries are in the combo 
box for Column 1), you will not be able to do so without manually skimming the 
cell entries.  This should be a relatively easy fix, but one that I feel needs 
to be done.  Thank you for your help

Robert