My code samples were complete... just cut 'n pasted directly from my source. I just tried naming the key directly instead of relying on keys %$format and got the same, "change-all-objects-everywhere" behavior.

I'll agree with the "something is definitely wrong" part... I've isolated everything down to the subs I referenced, because I've tested all the values of $self->{cell_format} in the subs immediately before assignment, and then immediately after and the assignment is definitely the culprit.

Gary Blackburn
Trained Killer