Yes, you heard me right. According to my Wii, my best time for 20 balloons is now officially zero, nada, no time at all.

Actually, what happened was that I let my controller hang from my wrist by its strap for 5-10 seconds, apparently at the wrong moment. The screen went all black, with a radar screen that was also all black except the white ring and the little arrow in the centre. In the middle of the screen was a weird white shape. I was able to push the + button and "Restart", and I heard the fanfare and was told that my best time for all 20 balloons was 00:00.00. Also my bike had no Mii on it, and a weird huge shadow under it. I fell off a cliff and got my Mii back, but only until I ran over a normal (non-launcher) ramp. I bailed out all the way to the Wii menu, switched off and on, and it is all back to normal.

Aside from the 00:00.00 time.

The lesson: be very careful about not letting the controller hang by its strap while cycling, because there is a bug there somewhere.

Whoa! So you still have 00 time? I can't imagine the bike without the Mii!

Yup, it is still there with 00 today. Bah, no more precise records for me.

Great! You now on an unbeatable first place forever.

I'm sure that is irritating because you can't tell what you do each time now. Wonder if they would give you a new game? It's their bug.

No cynique need no new game but "someone" should correct the wrong entry's in the RFNP/data.bin or in the RSPP/data.bin file. After a short view with an hex-editor I think these are heavy encrypted and only Nintendo could help.
An other solution is to kill the Mii and create a new, but all entry's of this Mii will lost.
I think cynique don't want to read this, but only a playback from an backup (the "private" folder on the SD-Card) would really help.

That's more or less what I figured. Bah. I guess I'll submit a bug report on Nintendo's site and see if there is any meaningful feedback.

Let us know what they say. I hope you can get your records back! At least the missing Mii showed up.

Only for safety: Before you gave your Wii to Nintendo copy most data as possible to an SD-Card using Wii system data menu and the slot under the front cover.

But you can't tell what you do each time anyway, can you? On the balloon ride, you only ever see your best time--no matter how long it takes you. At least that is how it is for me.