At one point, Sheldon suspected that the restaurant was substituting oranges for tangerines in their Tangerine Chicken. Leonard intended to take Penny to Szechuan Palace on their first real date (May 2008), but when they saw Sheldon there arguing with Chen, they left to go somewhere else (0117).
In order to divert his attention away from what happened to the cushion on his "spot" on the couch, Leonard told Sheldon that the Szechuan Palace had closed two years ago but that Leonard had been bringing Sheldon food from another restaurant (Golden Dragon) disguised in Szechuan Palace boxes. Sheldon is horrified. This is an inconsistency since the boys had been to Szechuan Palace several times since Leonard said it had closed (0216).
In January 2010 the (reopened?) restaurant redid its menu, much to Sheldon's horror: "General Tso's chicken" is no longer listed under "Specialties" but under "Chicken". In addition, under "Seafood" they offer "Shrimp with mobster sauce", which Leonard and Howard interpret as a typo, while Raj thinks it's "the sauce that mobsters like" and Sheldon is rather puzzled (0313).