Arg! Did not anticipate strings to have not length(x+1) :-D

oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java

@@ -240,8 +240,8 @@ public class SetDeliverer {
               // Divide ID and title.
               String combined = b.getKeyAsString();
               int indexOf = combined.indexOf(DH_COLLECTION_FILTER_NAME);
-              String id = combined.substring(0, indexOf);
-              String title = combined.substring(indexOf + 1);
+              String id = combined.substring(0, indexOf - 1);
+              String title = combined.substring(indexOf);
               // Set set.
               SetType newSet = new SetType();
               newSet.setSetSpec(id);