Panic after Ubuntu update

[beamends <..hidden..>]

Hi all,
once again the Ubuntu upgrade has failed, but now having a working
machine I can't log into LedgerSMB - I can connect to Apache2 ok, but
when LSMB goes to start up things go wrong. I can log into Postgres/psql
ok. After much faffing I think the problem is this (output from running
login.pl in a terminal :

..hidden..:~$ '/usr/local/ledgersmb/login.pl' 
Can't locate LedgerSMB/Sysconfig.pm in @INC (@INC
contains: /etc/perl /usr/local/lib/perl/5.10.0 /usr/local/share/perl/5.10.0 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /usr/local/ledgersmb/login.pl line 52.
BEGIN failed--compilation aborted at /usr/local/ledgersmb/login.pl line
52.

The Apache error log has:

[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Math::BigInt:
couldn't load specified math lib(s), fallback to Math::BigInt::FastCalc
at LedgerSMB/Form.pm line 36
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Can't locate
MIME/Lite.pm in @INC (@INC
contains: /etc/perl /usr/local/lib/perl/5.10.0 /usr/local/share/perl/5.10.0 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at LedgerSMB/Mailer.pm line 39.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] BEGIN
failed--compilation aborted at LedgerSMB/Mailer.pm line 39.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Compilation failed
in require at LedgerSMB/Form.pm line 39.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] BEGIN
failed--compilation aborted at LedgerSMB/Form.pm line 39.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Compilation failed
in require at LedgerSMB/Sysconfig.pm line 7.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] BEGIN
failed--compilation aborted at LedgerSMB/Sysconfig.pm line 7.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Compilation failed
in require at /usr/local/ledgersmb/login.pl line 52.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] BEGIN
failed--compilation aborted at /usr/local/ledgersmb/login.pl line 52.
[Fri Oct 16 09:05:06 2009] [error] [client 127.0.0.1] Premature end of
script headers: login.pl

Any ideas - thsi is driving me nuts!

Cheers
Richard