Same Errors for Multiple Contribution Installations

[iZilla_Pod]

I have attempted to install a few contributions on my site lately that each produce the same errors when installed (each is installed separately once the database has been restored after a failed installation). These are not contribution-specific errors because I get the same errors for multiple contributions.

If I run the SQL files to finish the installation of one of these contributions and then I refresh a product page I already had open, the contribution will work fine. But as soon as I navigate away from that product page and go to another product page (or even go back to the original one) my site stops working and I get the following errors:

Warning: Variable passed to each() is not an array or object in /home/izillapo/public_html/includes/classes/db/mysql/query_factory.php on line 114

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/izillapo/public_html/includes/classes/db/mysql/query_factory.php:114) in /home/izillapo/public_html/includes/functions/sessions.php on line 102

Warning: Cannot modify header information - headers already sent by (output started at /home/izillapo/public_html/includes/classes/db/mysql/query_factory.php:114) in /home/izillapo/public_html/includes/init_includes/init_templates.php on line 78

I don't understand what the errors are saying, but it seems to be a session problem. This might explain why the contributions stop working once I navigate away from the original page. I can easily fix the errors by restoring a database backup - so the issue is obviously a database one. I am using ZenCart version 1.3.6 and I'm installing the appropriate contribution versions that are compatible. Please advise.

[Kim]

What version of php and MYSQL?

[iZilla_Pod]

PHP Version: 4.4.8 (Zend: 1.3.0)
Database: MySQL 5.0.45-community-log

[iZilla_Pod]

The problem conveniently disappeared after I switched the database cache method from "database" to "file". Therefore, it appears the issue was with the caching on my server.