After purchasing the Cart66 e-commerce plugin, I noticed this in their docs:
WP Super Cache*
Even after its deactivated and deleted, WP Super Cache sometimes leaves content in the .htaccess file which can break the cart functionality.
*Note: Caching plugins cannot be used with any e-commerce site as it breaks the sessions used to store cart information.
In initial testing, Cart66 actually seems to work fine with WP Super Cache installed. But, I assume that the developers of Cart66 must have a reason for saying these things.
Is there a way I can be sure that they'll work together? For example, will PHP caching mode resolve the issue they warn about? Or can I exclude certain pages or functions from the cache to resolve this?