I've been programming with the default versions of LPDIRECTDRAW and LPDIRECTDRAWSURFACE for two years now. Since 7.0 came out, I thought I should use the 7 version of both pointers. With the proper syntax in, I cannot run any of my programs anymore! What gives?

Problem aside, my question is there any real speed increase that I'm missing out on if I stick with the default?

There's not that much increase in speed but there's more added features. And for your problem, make sure you're setting everything up correctly.