Hello, I have had my 50D for a few months and have just recently been giving it a true workout. I primarily shoot sports photography (team and individual). Through the winter and early spring, I shot single teams and it has been pretty good. I have recently had two all day events in which I shot entire leagues 30+ teams in one day, one athlete after another. I have noticed several problems both days and I have not been able to find an answer for these problems. I'm hoping somebody could enlighten me. First, I shoot in manual mode and use a lot of fill flash, pop-up flash with diffuser (to help with the shadows under the athletes hats). All works fine for the first 15-20 photos, then the problems begin. I begin to receive a "busy" message from the camera. The "busy" lasts for 10-15 seconds before I can take my next photo. This really stinks when you have an athlete standing there waiting and waiting. If I get a break, turn my camera off for a little while, then start again, it's ok for the first 15-20 photos and begins again. Second, I noticed the flash was not firing. It would fire for some photos, then wouldn't fire for others. It consistently did this all day long. Any ideas on these problems or suggestions on what type of setup approach I could take to provide better photos would be greatly appreciated. Thanks in advance.