Large numbers w/Perl

[Homer]

Kubuntu 10.04

This may be more of a Perl question, but thought some (K)ubunters
might have run into this.

With Perl in the past I have used Date::Manip without issue.  I've
just recently tried running some code that I know used to work, but
now doesn't.  The issue seems to be in the integer size I am sending
to DateCalc.  Any seconds I input up to and including 2147483647 work.
 Greater than that number gives garbage results.  That number is the
maximum value for a 32-bit signed integer.  I have verified the code
works on a Debian box, but does not on two (K)Ubuntu (both 10.04) that
I have tried it on.  I have tried Math::BigInt, Math::BigFloat, and
bignum without success.