WPEC: 188.8.131.52 (upgraded from 184.108.40.206 yesterday)
Upgraded to 220.127.116.11 yesterday and soon discovered that accessing any non-WPEC page or post was loading the products-page archive instead.
Upon further inspection, we discovered that every non-WPEC page or post is being matched against the main rewrite of (.+?)/?$ (as they should be). However the the matched rewrite query (via Debug Bar), shows that all slugs are assumed to be WPEC product categories. For instance:
That's kind of a deal breaker, especially since it's overriding the template.
This is with all plugins disabled except Debug Bar and WPEC. All rewrite rules introduced by theme functionality are disabled and rewrites flushed.