Dennis, I ran a test of the factory installed cluster list.  Here are the only ones still showing as valid, thought you could use this.  None of the rest were found.
73 Doug W5GA
6L0NJ      DXC.DX.OR.KR                        found
CS1SEL-5   HAMRADIO.ISEL.IPL.PT:41112          found
DB0LJ-6    DB0LJ.DYNDNS.ORG:41112              found
EI3IO      SHANDX.ATH.CX:5000                  found
EI7MRE     MAYODX.ATH.CX:7300                  found
GB7BAA     GB7BAA.COM:7300                     found
GB7DGK     GB7DJK.DXCLUSTER.NET:7300           found
GB7DXA     NT.AMERSHAM.NET:7300                found
GB7MBC     GB7MBC.SPOO.ORG:8000                found
HA6DX      DX.HU:9000                          found
IK4ICZ-6   IK4ICZ.DYNDNS.ORG:8000              found
IT9OBK-6   IT9OBK.ORG:41112                    found
IW5ECF-6   HAM.HOMELINUX.ORG:8000              found
IZ8BRI-6   IZ8BRI.DYNDNS.ORG:9000              found
JG1VGX-9   DXC.JG1VGX.NET:7300                 found
JH1RFM-9   JH1RFM.DDO.JP:8000                  found
K1EU       K1EU.DYNIP.COM                      found
K2LS       DXC.K2LS.COM                        found
K7AR       K7AR.NET:7300                       found
K8AZ       K8AZ.NO-IP.COM                      found
KN2M       KN2M.D2G.COM                        found
N2KI       DXC.N2KI.COM:7300                   found
N5IN       DXSPOTS.COM                         found
N5IN       DXSPOTS.NET                         found
N7OD       N7OD.PENTUX.NET                     found
N9MW       
WWW.N9MW.COM                        found
OK0DXI     RADIO.NAGANO.CZ:41112               found
PA1RBZ     PA1RBZ.DYNDNS.ORG:9000              found
RW3XA-8    DX.OBNINSK.ORG:8000                 found
S50DXS     S50DXS.ODS.ORG:8000                 found
SM4ONW-7   CLUSTER.SK4BW.NET:8000              found
SM7GVF-6   SM7GVF.DYNDNS.ORG:3692              found
VA3MW-7    VA3MW.HOMEIP.NET:41112              found
VE3CGR-5   VE3CGR-LINUX.DYNDNS.ORG:7300        found
VE6DXC     DXC.MIDDLEBROOK.CA:8000             found
VE7CC      DXC.VE7CC.NET                       found
W1AAA      DXUSA.NET:7300                      found
W1NR       DXC.W1NR.NET                        found
W3LPL      DXC.W3LPL.NET                       found
W6KK       W6KK.ZAPTO.ORG:7300                 found
W6RFU      128.111.56.240:7300                 found
73 Doug W5GA