Stompzi

I assume you're using Asio4All, rather than actual ASIO drivers for your card. Basically, Asio4All requires exclusive access to your sound card (nothing else using it) to operate. Make sure you close anything else that is using that sound card before you open FL (youtube usually catches me out ). For some reason, ever since I upgraded to Windows 7, it'll just randomly fail to get exclusive even when nothing else is using the sound. This sounds like what you experienced - you can usually poke it into behaving again by opening FL, switching to a difference soundcard (or unchecking the little check box next to the one you use) in the ASIO config, closing FL, opening FL again, and re-enabling. I have NO idea why this works, it makes no sense, but then ASIO4ALL is basically a hack anyway, so it's to be expected that it has a few quirks.