Index: /trunk/src/org/openstreetmap/josm/tools/ImageProvider.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/tools/ImageProvider.java	(revision 11020)
+++ /trunk/src/org/openstreetmap/josm/tools/ImageProvider.java	(revision 11021)
@@ -766,4 +766,14 @@
 
     /**
+     * Clears the internal image cache.
+     * @since 11021
+     */
+    public static void clearCache() {
+        synchronized (cache) {
+            cache.clear();
+        }
+    }
+
+    /**
      * Internal implementation of the image request.
      *
Index: /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/MapPaintPreferenceTestIT.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/MapPaintPreferenceTestIT.java	(revision 11020)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/MapPaintPreferenceTestIT.java	(revision 11021)
@@ -24,4 +24,5 @@
 import org.openstreetmap.josm.gui.mappaint.mapcss.MapCSSStyleSource;
 import org.openstreetmap.josm.gui.preferences.SourceEditor.ExtendedSourceEntry;
+import org.openstreetmap.josm.tools.ImageProvider;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -53,4 +54,5 @@
     @Test
     public void testValidityOfAvailableStyles() throws Exception {
+        ImageProvider.clearCache();
         Collection<ExtendedSourceEntry> sources = new MapPaintPreference.MapPaintSourceEditor()
                 .loadAndGetAvailableSources();
@@ -97,4 +99,5 @@
             }
         }
+        ImageProvider.clearCache();
         assertTrue(allErrors.toString()+"\n"+allWarnings.toString(), allErrors.isEmpty() && allWarnings.isEmpty());
     }
Index: /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/TaggingPresetPreferenceTestIT.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/TaggingPresetPreferenceTestIT.java	(revision 11020)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/preferences/map/TaggingPresetPreferenceTestIT.java	(revision 11021)
@@ -20,4 +20,5 @@
 import org.openstreetmap.josm.gui.tagging.presets.TaggingPreset;
 import org.openstreetmap.josm.gui.tagging.presets.TaggingPresetReader;
+import org.openstreetmap.josm.tools.ImageProvider;
 import org.xml.sax.SAXException;
 
@@ -50,4 +51,5 @@
     @Test
     public void testValidityOfAvailablePresets() throws Exception {
+        ImageProvider.clearCache();
         Collection<ExtendedSourceEntry> sources = new TaggingPresetPreference.TaggingPresetSourceEditor()
                 .loadAndGetAvailableSources();
@@ -84,4 +86,5 @@
             }
         }
+        ImageProvider.clearCache();
         assertTrue(allErrors.toString(), allErrors.isEmpty());
         assertTrue(allMessages.toString(), allMessages.isEmpty());