When selecting a product and then selecting a color of bag (something you have to do), it would then send the user to a page with multiple products instead of keeping the user on the same page and allowing them to ad to cart:

www.lovely4bags.com/hand-bags/hand-bags/...th%20brown&size=

This URL likely won't work because the plugin is now disabled, but perhaps the URL structure eludes to what the issue may be.

Hi,
In JoomSEF's Configuration on the Advanced tab set "Set page base href value" to "Yes - always use only base URL".