Internal Server Error saving Purchase Transaction

["Nick Prater" <..hidden..>]

I'm using ledgersmb 1.3.20, installed from the sourceforge tarball,
running on an Ubuntu 12.04 machine.

When I try to save a Purchase Transaction, I get an internal server error.
The apache error log reports the following:

[Fri Jul 20 08:43:32 2012] [error] [client 127.0.0.1] Math::BigInt:
couldn't load specified math lib(s), fallback to Math::BigInt::Calc at
LedgerSMB/Form.pm line 61, referer: http://localhost/ledgersmb/ap.pl
[Fri Jul 20 08:43:32 2012] [error] [client 127.0.0.1] Can't call method
"is_zero" on an undefined value at /usr/share/perl5/Math/BigInt.pm line
1197., referer: http://localhost/ledgersmb/ap.pl
[Fri Jul 20 08:43:32 2012] [error] [client 127.0.0.1] Compilation failed
in require at /usr/local/ledgersmb/ap.pl line 7., referer:
http://localhost/ledgersmb/ap.pl
[Fri Jul 20 08:43:32 2012] [error] [client 127.0.0.1] Premature end of
script headers: ap.pl, referer: http://localhost/ledgersmb/ap.pl

Math::BigInt is version 1.997, installed via the standard Ubuntu packaging
(apt-get install libmath-bigint-perl). This corresponds with the latest
available on CPAN

I can side-step this issue by removing Math::BigInt (apt-get remove
libmath-bigint-perl), which allows me to save purchase transactions,
however I believe that will cause problems for other parts of ledgersmb.

Searching the mailing list and looking at past ledgersmb changelogs, I can
see various fixes have been applied for "is_zero" errors in the past (such
as in 1.3.17 and 1.3.3).

I also see suggestions to install perl modules from CPAN rather than using
the distribution's package manager. I believe I am running the latet
versions of ledgersmb and relevant perl modules, so that fix/workaround
doesn't seem to apply.

I'll continue digging around to see if I can gain a better understanding
of the issue, but I wonder if this a known problem, with an official
work-around?

Many thanks and best wishes,

Nick