We're seeing a problem in Excel that I've never come across. All of the
machines that we're seeing this on just downloaded this month's auto-update,
but I haven't looked yet to see if there were any Office fixes. I'm
wondering if any of you are seeing this or might have a solution for me.

We typically work with 16-digit credit card-style numbers, where the entire
number is treated as text. Typically, trying to format the number as text
results in scientific notation, so I usually leave it as a number with no
commas or decimals. However, no amount of formatting seems to affect this
issue.

When I enter a number in to a cell, if it is longer then 15 digits, any
number after 15 changes to a zero. You can see in the example I've pasted
below where I was typing in all 4's ending with a 3, from 2 digits to 17
digits long. Even if you go to edit the data, the last numbers have been
changed to a 0, it's not just how the formatting is showing the number.

43
443
4443
44443
444443
4444443
44444443
444444443
4444444443
44444444443
444444444443
4444444444443
44444444444443
444444444444443
4444444444444440
44444444444444400

Am I missing something? Help!

Thanks!!
beth