Why use dependant codes while there are standards?
utf-8 is a standard, and it's recommended by the w3c.
I had to check everything because it didn't show up right on my system.
Then you set something up improperly in the first place and instead of fixing it you tried to find a workaround. You drew the wrong conclusions, I'm afraid. Use the original file and set encoding to utf-8 (unicode) in coppermine's config. For details, start another thread, as this isn't actually a support thread.
dutch.php will mostly be used on/by Dutch people I guess and they won't have all utf-8.
Trust me: everyone has utf-8. In your browser, it may be labelled "unicode". Out of the box, all major browsers are set to display utf-8 encoded pages by default (automatic encoding). It's part of the HTML standards - you define an encoding in the header, and nearly all browsers (IE4 or better, Firefox, Opera, Safari etc.) recognize the encoding and display them automatically.
You don't have to use my file, I made it for myself and thought it could be usefull for others.
I'm aware that I don't have to use your file, thanks. I just replied for the benefit of others, to make sure that others don't use your file as a workaround for their encoding issues. When using your file, you'll run into issues sooner or later.
As suggested above: if you want to find out more details, start a thread of your own on the support board. If you think that my advice doesn't apply to you and want to use your modified version, then go ahead and use it at your own risk.