Troubleshooting Sharepoint 2010 User Profile Synchronization Error

When implementing my Sharepoint 2010 testlab I configured user profile synchronization. After a while I noticed that Sharepoint failed to import new user accounts from my Active Directory.
I checked the configuration in Sharepoint, which seemed allright. But when I checked the eventviewer I noticed some problems:

Log Name:          Application
Source:            FIMSynchronizationService
Date:              3/7/2012 9:38:10 AM
Event ID:          6801
Task Category:     (3)
Level:             Error
Keywords:          Classic
User:              N/A
Computer:          SRV1.contoso.com
 

Description:
The extensible extension returned an unsupported error.The stack trace is:"System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> Microsoft.Office.Server.UserProfiles.UserProfileApplicationNotAvailableException: No User Profile Application available to service the request. Contact your farm administrator. at Microsoft.Office.Server.UserProfiles.ProfileManagerInstance.GetApplicationProxy() 
Microsoft.Office.Server.UserProfiles.ProfileImportExportService.InitializeProfileImportExportProcess()
 
Now we know what the problem is.
There seems to be a problem with the Exensible Connectivity Agent.

• Open miisclient
  (%programfiles%\Microsoft Office Server\14.0\Synchronization Service\UIShel\miisclient.exe)  
• Check the Operations tab. In my case the following error was reported: stopped-extension-dll

 
Now it seems that a bad URI has been configured in FIM which we need to correct.

• Launch miisclient.exe 
• Select the Management Agents tab 
• Select the Extensible Connectivity agent and select properties
  

•  Click on the "Configure Connectivity Information" option

• Now let's focus on the "Connect To" option

• Correct the URI in the textbox
  syntax:    direct://{HOST}:{PORT}/..

• Close FIM, restart your synchronisation and everything should be running again.

In my case it was pretty easy, since I changed the port number of Central Administration after I configured user profile synchronization. I didn't realise that the port number wouldn't be changed in FIM.