Not sure I explained myself properly.
What I was trying to say is:
1. use Normal image or picture box for the background as this doesn't require transparency,
2. use Lavolpe component for all other image that require transparency.
You'll achieve better speed that way as Lavolpe component is running a lot of subroutine in the background and (correct me Lavolpe if I'm wrong) Background image doesn't require all of what Lavolpe component is doing.
also I don't know your level of expertise in programmation, so ensure your subrountine is all fine tuned in order to use maximum speed. Use API as much as possible instead of low Vb6 class like PSET and such if you require them. I never saw a pokemon game, therefore I don't know what you're trying to achieve, but I once did a replica of Starcraft (not all the game, just the running 191 frames of the intro where you decide wich game type to choose)) with Lavolpe component, so I know the component can handle a lot of stress and action when used correctly.
I'm rather pretty busy right now but I'll do my best to answer your answer if you have any.