we have a problem with "Corporate 2" After updating to PHP 5.2.17

Dear Sirs, we have a problem with "Corporate 2" template used on the customers website.

Company providing server services for our customer updated PHP, and after that some problems occured, which we don't know how to solve.
Before updating everything has been working perfectly - The previous PHP version was 5.2.9.

After updating to PHP 5.2.17 following erros occured:


Apache log errors:

[Tue Jun 07 13:48:18 2011] [error] [client 213.184.18.3] PHP Notice:
Undefined variable: inset2 in
/srv/www/vhosts/laboratorium.pan.olsztyn.pl/templates/gk_corporate2/layouts/blocks/main.php
on line 17
[Tue Jun 07 13:48:18 2011] [error] [client 213.184.18.3] PHP Notice:
Undefined index: additional_class in
/srv/www/vhosts/laboratorium.pan.olsztyn.pl/templates/gk_corporate2/html/modules.php
on line 109
[Tue Jun 07 13:48:18 2011] [error] [client 213.184.18.3] PHP Notice:
Undefined index: additional_class in
/srv/www/vhosts/laboratorium.pan.olsztyn.pl/templates/gk_corporate2/html/modules.php
on line 109
[Tue Jun 07 13:48:18 2011] [error] [client 213.184.18.3] PHP Notice:
Undefined index: additional_class in
/srv/www/vhosts/laboratorium.pan.olsztyn.pl/templates/gk_corporate2/html/modules.php
on line 109


General error 500 (Internal server error)



The previous configuration can can be found here: laboratorium.pan.olsztyn.pl/oldphp.html.
After updating - here: laboratorium.pan.olsztyn.pl/test.php


The website works on 1.5.20 joomla in "Compatibility mode": 1.0 and mysql Ver 14.12 Distrib 5.0.26, for suse-linux (i686) using readline 5.1.