I was configuring User Profile Service at one of our clients, and the problem was that after provisioning User Profile Service I was getting 6801 and 6803  errors in event log.

Central Administration site was using SSL, for example https://sharePointServer

Following examples at http://www.mylifeinaminute.com/2010/07/07/sharepoint-2010-user-profile-synchronization-errors/ I tried to fix things, but it didn't work for me...

So, after using ULS Viewer and miisclient (C:\Program Files\Microsoft Office Servers\14.0\Synchronization Service\UIShell\miisclient.exe) I found out that User profile service can not connect to the approprite Web Service.

What I did was, I opened up a miisClient, opened Management Agents, right clicked on MOSS{guid} Extensible connectivity, clicked on Properties and Configure Connection Information. After trying to configure the right connection, I found out that even though Central Administration site is on URL https://sharepointserver, the user profile connection instead of connecting to direct://sharepointserver/_vti_bin/ProfileImportExportService.asmx?ApplicationID=27c26eca%2D6eeb%2D4da4%2D9012%2Da51e02baae9a, I entered:https://SharePointServer.xnet.si/_vti_bin/ProfileImportExportService.asmx?ApplicationID=27c26eca%2D6eeb%2D4da4%2D9012%2Da51e02baae9a and everything started to work normaly.

I hope that helps