Using DNN 4.5.5.  Recently, I have lost the ability to login to child protals.  I have been using DNN for a long time and have never had this happen.   The last things I have done is to install FotoVision and effority.UserDirectory modules.  I have uninstalled them, but I think this is unreleated.  I see this message repeating in the Event Viewer since the problem started:
  Category:  Web Event.  Event 1315.  Source ASP.NET 2.0.50727.0.

Event code: 4005
Event message: Forms authentication failed for the request. Reason: The ticket supplied has expired.
Event time: 8/12/2007 8:45:30 AM
Event time (UTC): 8/12/2007 2:45:30 PM
Event ID: 55ffa1de49094db8aa26c6d8af3b8656
Event sequence: 153
Event occurrence: 1
Event detail code: 50202
Application information:
Application domain: /LM/W3SVC/374356648/Root-1-128313885671008345
Trust level: Full
Application Virtual Path: /
Application Path: C:\Inetpub\Springs\
Machine name: WEB01
Process information:
Process ID: 5856
Process name: w3wp.exe
Account name: NT AUTHORITY\NETWORK SERVICE
Request information:
Request URL: http://www.springsontheweb.com/Default.aspx
Request path: /Default.aspx
User host address: 10.1.17.1
User:
Is authenticated: False
Authentication Type:
Thread account name: NT AUTHORITY\NETWORK SERVICE

I have already tried IISRESET and restarting the server.  I can log into the parent portal without issues.  The issue is with all the subsites.  For example, I can  log into corliss.ws, but I cannot login to springsontheweb.com or any of its children.