Very odd issue with my Simpsons Pinball Party.

I started a game and found that loads of switches were not registering, took off the glass and sure enough loads don't trigger, but a tiny amount do.
So put the game in diag mode for switches and they all checkout!

Start a game and again loads don't work, left outlane is ok, pops are ok, skate board is ok but that's about it.
Again put the game in diag mode for switches and all switches trigger when I touch them, even ran through coil test and all coils appear fine.

So why when playing a game do they not work but in diags they are fine>?

Any help appreciated.

Thanks for the help.

I have found the solution, took the batteries out with machine off so the game was 'reset' as a few folks had said and that has fixed the issue.
Lost my high scores etc but at least the game is now working again.

What an odd issue and fix....

Must be a bug in the code that crops up once in a blue moon, very odd though.