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.
I'm not a MultiBit expert, but I suspect that those aditional ".wallet" files are just backup copies.
I suspect that you can install the 0.4.22 upgrade and your wallet will be fine, but I'd create a backup copy off the computer (perhaps to a USB drive) just in case of disaster. Perhaps backup all the files, and then figure out which of them you actually need to recover if the upgrade doesn't behave as expected.
Another option would be to find out how to export the private key for the address before you do the "downgrade". You could write (or print) that private key to a piece of paper. As long as you have the correct private key, you'll be able to regain control of the bitcoins even if MultiBit becomes completely unusable for you. That private key can be imported into another wallet, or swept back to MtGox if necessary.