I got this error log.
When update from client, it show software up to date.
When check server, have the below error log.
[Tue Jul 31 20:44:56 2012] [error] [client 192.168.1.4] Jul 31 20:44:56 server.maccity.private SoftwareUpdateServerGetCatalog[2138] <Debug>: REQUEST FOR CATALOG: /index-lion-snowleopard-leopard.merged-1.sucatalog
[Tue Jul 31 20:44:56 2012] [error] [client 192.168.1.4] Jul 31 20:44:56 server.maccity.private SoftwareUpdateServerGetCatalog[2138] <Debug>: HTTP HOST: 192.168.1.90:8088
[Tue Jul 31 20:44:56 2012] [error] [client 192.168.1.4] Jul 31 20:44:56 server.maccity.private SoftwareUpdateServerGetCatalog[2138] <Debug>: DOCUMENT ROOT: /Users/maccitymlk/Downloads/html
[Tue Jul 31 20:44:56 2012] [error] [client 192.168.1.4] Jul 31 20:44:56 server.maccity.private SoftwareUpdateServerGetCatalog[2138] <Debug>: LINES WRITTEN: 15
OS X Server