Just yesterday I downloaded many of the "musical" applications for the iPhone (1st Gen), such as MiniPiano, Violin, and DigiLite, but the sound doesn't work on any of them! The same with the BubbleWrap, Crazy Disco, and Wooo! Button applications. But the applications I downloaded earlier, such as Ocarina, makes the sounds perfectly. Any ideas as to what's going on? The volume is all the way up, and the headphones aren't plugged in, just as a side note.