Is Google overriding your x-cart titles or x-cart meta descriptions?

If you've used customized your x-cart page titles and x-cart meta descriptions, and not had them show up in search engines, it could be because Google hasn't yet reindexed your x-cart pages, or it could be because Google thinks what they're showing is more relevant to the search.

Matt Cutts recently spoke on the changing of snippets and page titles and how Google decides what's relevant: