I was demonstrated once a situation where you could rename a field item
in a Pivottable the same as another field item in that field which
would cause it to group together (not affecting the underlying data ie
the data you see when you do the drill through but just the data used
by the pivottable, the cache). This is a difficult action to reverse as
there is no way of selecting the items you want to ungroup if the field
is not a pivottable grouped field (ie not in the underlying data but a
new field in the pivot table). I believe this can not be corrected even
with a refresh.

Unfortunately (or fortunately depending on how you look at it) I have
not been able to replicate this error again and I was wondering if
anyone had experienced this situation?

I've tried do the same action but only experienced this causing the
fields items to swap around (resort). I'm wondering if perhaps the
person who demonstrated this to me was using an older version of excel
or had some table option set differently? His pivot table was part of a
vba enhanced tool and so perhaps there was some hidden setting which he
had different too?

If anyone has experienced this please let me know as I'm creating a vba
enhance pivot table tool and would like to make it as robust as
possible and this potential problem would require some attention.

Thanks in advance