Unable to play original games

I have installed Homebrew and Bootmii and even though that works fine now, I'm unable to play original (purchased) games anymore. The channel (top left) says "Upgrade system software" and when I click on it it displays a similar message.

What can I do?

What's also strange is that I can play original games through Neogamma ... Would still like to get the 'old' method working again.

Upgrade the System Software. That will stop the message and will make the games work again. It will do absolutely no harm to HBC or any other legitimate homebrew stuff. Don't mention neogamma here again please, that is a backup loader which is against the rules here.