For the Mew problem, check 'fateful encounter' and make where you met him 'fateful encounter' and it works just fine.
Now for a new problem. Pokemon Emerald, Wurmple, and the PID generator. I have a female Hardy one that will change into Caskoon. I want to make a female Brave Wurmple one that will turn into Caskoon. When I try to put those in, however, and select 'generate', the program hangs indefinitely! Note that if I make pretty much ANY change to the information, the control for the evolution switches from Caskoon to Skoon.