Looked into it and from the support forum it would appear others have had the same problem. So far there appears to be no fix. However, the new version of IBPro arcade has literally just been released. When all the bugs are sorted I'll install that and reset all the games to zero again.
Thanks, I thought I'd lose all my hard work on getting second place, going for 1st so Hornmeister watch out!
In still have auto pruning turned on. This will remove the highscore after 30 days of it being there.