Compatibility with other plugins
Compatibility
eShop has been written for WordPress 3.0 and above. It is not compatible with earlier versions of WordPress.
Affiliates
Now compatible with WP Affiliate for affiliates.
Shortcodes
Compatible with eShortcodes. (WP version 3 specific)
WPMU Membership
This plugin interferes with eShop shortcodes unless you enable them within WPMU Membership.
Conflicting Plugins
eShop may conflict with other plugin that you have installed. If you encounter any conflicting plugins, please post their details on the support forum.
Automatic faceBook Converter
Appears to interfere with eShop’s sessions and/or redirection.
Bad Behaviour
We cannot support the use of eShop with this plugin at the present time. However for those that still wish to use it, so far as we can tell, there are no conflicts. But you will have to visit the Paypal Go Live Checklist and add all of the IP addresses to Bad Behaviour’s whitelist.
Caching Plugins
Caching plugins are known to cause significant problems within eShop and we cannot support their their usage. eShop has been amended to try and work with WP Supercache but it will not work correctly when using widgets.
Event Espresso
Currently conflicts with eShop’s papypal_class.
Facebook Like Thumbnail
Disables eShop’s checkout and removes access to orders in the back end of a site.
Maintenance Mode
Maintenance Mode must be deactivated when testing eShop, otherwise Paypal can not interact with the site. Please note that you no longer need any maintenance mode plugins for WordPress 3 or above as this functionality has now been added to the WordPress core.
Sociable
Has been known to cause some problems with eShop functionality.
jadedcoder Sticky Permalinks
Unknown issues.
Theme My Login
Causes issues with eShop forms — especially the Add to Cart functionality.
WP Member
May hide the My Order menus from logged-in customers. No known workaround at present.
Yet Another Related Posts
Disable this plugin before upgrading or deactivating/reactivating eShop, as it may be the cause of some incompatibility issues.

FlipFlop 3.0