What you're describing is a known "feature" of Excel.

Debra Dalgleish describes the issue in the below website (along with some
workarounds):
http://www.contextures.com/xlautofilter02.html#Limits

Does that help?
***********
Regards,
Ron

XL2002, WinXP


"Reid_co" wrote:

I have a spreadsheet with close to 12,000 rows and 7 columns of data , and
have filters on each of the columns. As of this past Tuesday, the filter
stopped showing data past the letter S (info goes down to letter X). I
cannot fix this and neither can my IT dept.

Any one know how to correct this?

Thanks

Reid