Vossy, I don't think it's a problem of having 1.0.1 on your machine. I know of people with this firmware version that have Beat2X working. Have you ever been able to play it?
If so, can you try this? Delete 'settings.dat' from every pack folder and 'scores.dat' from 'data' folder (by deleting them you'll lose high scores and last songs played, so copy them to your HD before doing that). Does it work?
If it doesn't try starting the game with only one pack in your SD card.
And if it doesn't, try reinstalling everything with only one pack.
Sorry, but without seeing the contents of your folders that's all I can do.