[TYPO3-dev] Strange locallang.xml problem

[Brian Bendtsen]

Hi

Im suddenly getting some errors about my locallang.xml file in my extension.

I just added some labels and when trying to test it in the front end 
this error was displayed:

not XML: LINE 1 empty document or something like that.

I had not made other changes to the beginning of the doc. The only way 
to get rid of the message
was to make a new file and copy the data to it.

Now I receive the error:

Undeclared entity error when trying to insert special characters like 
æ

What going on?

/Brian Bendtsen