ok, I'll try to downgrade to 0.4.22.

What do I have to backup before I uninstall MultiBit?

In the original folder where I saved my wallet, are the following files:

walletname.info
walletname-20130430233733.key
walletname-20130501195242.wallet
walletname-20130501195442.info
walletname-20130501195442.wallet
walletname-20130501195442-20130501202028.wallet

Do I have to keep all these files and use them with version 0.4.22?

I also have to say that I only have ONE wallet, why are there 3 of them. Which wallet should I open with 0.4.22?

This is so confusing.