I want to specify a custom icon for a makrer. Sadly, the icon that I chose is not displayed.

Here's the relevant parts of the plugin.xml file (the project id "x"):

<extension
      id="xmlProblem"
      name="XML Problem"
      point="org.eclipse.core.resources.markers">
   <super type="org.eclipse.core.resources.problemmarker"/>
   <persistent
         value="true">
   </persistent>
</extension>

<extension
      point="org.eclipse.ui.ide.markerImageProviders">
   <imageprovider
         markertype="x.xmlProblem"
         icon="icons/marker.png"
         id="xmlProblemImageProvider">
   </imageprovider>
</extension>

I also tried specifying a class (implementing IMarkerImageProvider) instead of an icon, but that getImagePath() method of the class does not get called.

Any thoughts on how to make custom marker icons work?

Desperately, yours.

-Itay