error 500 with xampp for linux and joomla

Im using ubuntu and XAMPP for linux and I have a problem when I try to upload an extension greater than 500kb in Joomla, I get an "HTTP Error 500"

http://s4.postimage.org/7wgxcfveq/error500.jpg

My php.ini file is configured following the joomla recomendations:

"display_errors=Off"......

here is my error log

[Mon Jun 06 14:12:45 2011] [notice] suEXEC mechanism enabled (wrapper: /opt/lampp/bin/suexec) [Mon Jun 06 14:12:45 2011] [warn] RSA server certificate is a CA certificate (BasicConstraints: CA == TRUE !?) [Mon Jun 06 14:12:45 2011] [warn] RSA server certificate CommonName (CN) localhost' does NOT match server name!? [Mon Jun 06 14:12:46 2011] [notice] Digest: generating secret for digest authentication ... [Mon Jun 06 14:12:46 2011] [notice] Digest: done [Mon Jun 06 14:12:47 2011] [warn] RSA 开发者_开发技巧 server certificate is a CA certificate (BasicConstraints: CA == TRUE !?) [Mon Jun 06 14:12:47 2011] [warn] RSA server certificate CommonName (CN) localhost' does NOT match server name!? [Mon Jun 06 14:12:48 2011] [notice] Apache/2.2.17 (Unix) DAV/2 mod_ssl/2.2.17 OpenSSL/1.0.0c PHP/5.3.5 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 configured -- resuming normal operations [Mon Jun 06 14:15:34 2011] [error] [client 192.168.56.1] PHP Fatal error: Maximum execution time of 30 seconds exceeded in /opt/lampp/htdocs/csu/libraries/joomla/filesystem/archive/tar.php on line 154, referer: http://192.168.56.101/csu/administrator/index.php?option=com_installer&view=install

The PHP Fatal error is "Maximum execution time of 30 seconds exceeded".

You could try increasing this by altering the max_execution_time in the php.ini file or create a .htaccess file containing..

php_value max_execution_time 60

Should the installation of an extension take longer than 30 seconds?
There might be a script issue, such as an endless loop, that's causing problems.