Marius, have you done a clearcache? The new override system caches the override templates for speed, so you need to clear the cache for it to take effect.
That was what I had missed. Can I delete the design/demo folder, if I have created my own pagelayout.tpl templates under the folder design/(mydesign)? Or is it a "backup" ?
The design/demo templates are just examples. You do not need them at all. The design/standard is important not to change ( for upgrade issues ). The design/admin is the default admin templates. I would not recommend changing these (admin), but you can use them as a fallback design if you want to do modifications to the admin templates.
But there's some new issues now. If I delete the design/demo folder, and use the design/(my design)/override instead, the links forwarded to the different sections (for ex.: "<a href={"content/view/full/159/"|ezurl} />") becomes invalid, don't they?
Maybe it's a stupid question, but I rather ask first!