You may need to add a php .ini to the includes/classes directory - see this article:
http://www.tech-bits.com/index.php /CategoryID/1/EntryId/141/entry
If you needed to follow that to get your Ioncube loader working, then you need to copy the same php .ini file into the includes/classes directory to make it work, since SunShop calls the iverify class directly.