Tony Hawk American Wasteland SMB Freezing

I know the game's been proven compatible via an internal HDD, sadly I have one of the slim silver PS2s, so that isn't an option for me.

I start the game, it works fine. Start story mode, get to where I purchase clothing....and it freezes. I've tried waiting five minutes, so it's definitely frozen. When I go to restart it OPL tells me the VMC is having a problem. Tried it without VMC....same deal.

Anyone got any ideas on how to make the game work over SMB?

Don't know about SMB but the same thing happens on USB, it sometimes freezes when loading a level in free skate and classic mode also.