There’s something in the Q2 report that’s unnerving investors. Netflix shares are down 7.7% in after market trading. But it probably involves concerns about a potential slowdown in the company’s growth, because last quarter’s numbers look solid. Net income at $29.5M was +378% vs the period last year on revenues of $1.07B, +20.3%. The top line was right where analysts expected it to be. And profits at 49 cents a share topped the forecasts for 40 cents. Netflix ended the quarter with 29.8M domestic streaming customers, up 630,000 over the three months. That may explain the stock slip — some analysts hoped for a bigger pick up. But CEO Reed Hastings and CFO David Wells say the number is pretty good. Netflix typically sees a dip in Q2, and this year “was an exception, we believe due to the launch of Arrested Development.” They add that the show “already had a strong brand and fan base, generating a small but noticeable bump in membership when we released it.” Netflix reported 7.75M international streaming customers, +610,000. It also had 7.5M domestic subscribers for the DVD rental service, down about 495,000. Execs tipped their hats to competitors led by Amazon Prime and Hulu, describing them as “quite good and quite different.” Now that Hulu’s backers — Disney, 21st Century Fox, and Comcast — plan to keep and invest in the service “content prices may rise further, but we have many multi-year deals in place to mitigate this.”