On warning (Strict Standards) and optional modules

Hi

Successfully installed 1.mod_vm_rssgenerator1.2.zip, and it's working fine. But, in the cpanel, the following message is shown:

Virtuemart RSS feeds Generator
Strict Standards: Non-static method modVmRssGeneratorHelper::getCurrency() should not be called statically in /var/www/joomla_arigatosama.net/administrator/modules/mod_vm_rssgenerator/mod_vm_rssgenerator.php on line 11 Strict Standards: Only variables should be assigned by reference in /var/www/joomla_arigatosama.net/administrator/modules/mod_vm_rssgenerator/helper.php on line 12

Please give me information on how to fix it.

Also, I'll appreciate some more information on the two optional modules (i.e., 2-optional.mod_vm_catrss1.1.zip and 3.optional.plg_system_vm_rss_generator1.1.zip) because their documentation seems not to be available yet. What do they do, and what'd be better if they are installed?

Environment: PHP 5.3.10-1ubuntu3.13, Joomla! 2.5.24, VirtueMart 2.6.10.

Well, I dealt with the first one by changing
public function getCurrency()
to
public static function getCurrency()
in helper.php.

And the second one is gone by changing
$db = &JFactory::getDBO();
to
$db = JFactory::getDBO();
in helper.php


Hope these changes will be reflected in a new version.