Well, a while ago, when there still was a substantial number of Morpheus hosts in the search horizon of any LimeWire user, the amount of results coming from Morpheus hosts, or rather the lack thereof, was quite obvious. I think Greg Bildson dubbed it the "Morpheus black hole", but today it is almost impossible to tell whether Morpheus works or not from the perspective of a LimeWire user. If you don't see any Morpheus results, it may be because there are too few Morpheus hosts in your horizon.