Movie theater chains Regal and Cinemark are taking it on the chin on Wall Street this morning after a weekend of disappointing box office sales — and the close of an even more dispiriting quarter. Regal’s stock price is down about 4.6% in early trading. Janney Capital Markets downgraded its stock recommendation to “sell” from “neutral.” Lazard Capital and Merriman Capital also lowered their cash-flow projections for Regal. And Cinemark is down about 3.5%. Janney Capital changed its recommendation to “neutral” from “buy” — with Lazard and Merriman also cutting their forecasts. Analysts say that the 4.4% increase in box office sales in the second quarter vs. the same period last year fell far short of their forecasts: Lazard’s Barton Crockett expected a 10% pickup, while Merriman’s Eric Wold thought sales would improve at least 11%. And the holiday weekend didn’t lift their spirits. Crockett says that the $182 million generated domestically by Paramount’s Transformers: Dark of the Moon in its first seven days was $29 million less than he expected.