@hopechestjewelry: You haven’t provided enough information for your issue to be troubleshot, and the way to test this is by enabling caching types one by one until the shopping cart breaks.
@designskew: This is indeed an unnecessarily broad (not to mention incorrect) statement — W3TC works fine with virtually every theme available. Many users simply enable all caching types without testing, and wonder why their site is broken (it’s typically minify that requires testing, particularly with JS).
@haddow777: A w3-total-cache-config.php file does indeed remain on the filesystem in the /wp-content/ directory following deactivation/deletion of the plugin.
Upon deactivation, W3TC removes the directives written to the .htaccess file, but it can be inspected to be sure nothing was left behind.
W3TC is a fine plugin for use right out of the box, and ships with conservative settings that work for most people — it simply requires testing for optimal use.
