Thanks for checking it with 7zip.

What it sounds like is that the script is over running the memory setting of php.

If you can control php settings in your .htaccess file try these settings.

php_value upload_max_filesize 30M
php_value post_max_size 30M
php_value max_execution_time 400
php_value mysql.connect_timeout 240
php_value memory_limit 1024M

Skip