I join the club.
Exactly the same happened to me.
Around the black 18 March I was sweeped out from Inktomi (after having been on the 1st page for more than a year!), then signed up with SiteMatch... approved... then nothing. When I check Overture/SM panel, there is no clicks recorded at all since the beginning of April. What is then SiteMatch about? Collecting a few thousands of $50?
If I was good enough for Yahoo for more than a year, then what the hell did I commit to be punished to death?