Welcome to "Bally Bricks"!

Did you replace the targets with new ones? New ones brick a lot worse than originals.

There's not a lot to be done to fix these (well, there's been a lot done to TRY and fix this).... make sure the drops are as far forward as they can be in each slot, people have melted pieces of the drop off to try and get it to drop better.... one this it's not is the spring. You'd think it would be, but it's not.

If you look on rec.games.pinball newsgroup through google groups there's a ton of info there on what people have tried.