Everytime when I update tag info or e.g. ReplayGain adds information to files the console pops up whit the following error: "WARNING (CORE): Verboten!"
In the title bar of the File Info window it also displays: "[error updating file]"
The strange thing is, though, the tag does get updated. The changed value will be stored in the file anyway.

This problem occurs in foobar 0.7.1 and 0.7.2 when updating MP3 and OGG file tags.
My "MP3 tag writing" setting is set to "ID3v2"

In the preferences in the "Database" section there's an option "Don't write modifies tags to files", the problem occurs when the box is checked and doesn't when the box isn't checked.

The reason I checked it in the first place was because I wanted to avoid tags being written automaticly without my knowledge. I figured I might as well check it incase I missed a setting somewhere.
What I don't understand is what the point is of having an option like that if the tags are being stored anyway.

Could someone enlighten me on this one?

"dont write modified tags" should be self explaining. it means that changes in tags are written into the database itself instead of modifying the files. So you have tags, gain-infos and so on although not altering the files

See this thread:

http://www.hydrogenaudio.org/forums/index....howtopic=14462&

But the thing is, the information does get stored in the music file, not just the database.

How did you check this? Did you use an external application (such as Tag), or did you rely on foobar2000's file info box?

The file info box shows whatever metadata is in the database, it will only show you what's actually in the file if you tell it to do so (by clicking the "reload info from file" button).

I check it by using "reload info from file" and I check it in Winamp.