--- src/org/objectweb/util/ant/MultipleCopy.java
+++ src/org/objectweb/util/ant/MultipleCopy.java
@@ -10,6 +10,8 @@
 import org.apache.tools.ant.taskdefs.Copy;
 import org.apache.tools.ant.types.FileSet;
 import org.apache.tools.ant.types.PatternSet;
+import org.apache.tools.ant.types.Resource;
+import org.apache.tools.ant.types.ResourceCollection;
 
 import java.io.File;
 import java.util.StringTokenizer;
@@ -100,9 +102,11 @@
 			}
 		}
 
-		// deal with the filesets
-		for (int i = 0; i < filesets.size(); i++) {
-			FileSet fs = (FileSet) filesets.elementAt(i);
+		// deal with the ResourceCollections
+		for (int i = 0; i < rcs.size(); i++) {
+			ResourceCollection rc = (ResourceCollection) rcs.elementAt(i);
+			if (rc instanceof FileSet && rc.isFilesystemOnly()) {
+				FileSet fs = (FileSet) rc;
 			DirectoryScanner ds = fs.getDirectoryScanner(project);
 			File fromDir = fs.getDir(project);
 
@@ -110,6 +114,10 @@
 			String[] srcDirs = ds.getIncludedDirectories();
 
 			scan(fromDir, destDir, srcFiles, srcDirs);
+			} else {
+				throw new BuildException(
+					"ResourceCollections are not fully implemented");
+			}
 		}
 
 		// do all the copy operations now...