Maven editor extensions disabled for pom.xml

Hi,

this is probably a newbie question:
I use IDEA Ultimate 10.0.2 and the Maven editor extensions for pom.xml files stopped working. There is no highlighting or completion available anymore.

The only thing I did (as far as I noticed), was
- to create a new file,
- named it "pom-xml",
- saw the mistake, because IDEA did not know the file type
- changed the name in the dialog to "pom.xml"
.

The file generated was named "pom-xml". I renamed the file to "pom.xml" and then all support for all other pom.xml files was gone...

Any help appreciated.

Best regards,

  Torsten