I just logged in as Host after clearing out my browsers cache (not that this helped.... I am desparate)
I tried to reply to an existing post and got this message:

Error: is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Modules.Forum.PostConnector.PostToDatabase(Int32 TabID, Config objConfig, Int32 PortalID, ForumUser objForumUser, String PostSubject, String PostBody, ForumInfo objForum, Int32 ParentPostID, Int32 PostID, Boolean IsPinned, Boolean IsClosed, Boolean ReplyNotify, Int32 ThreadStatus, String Attachment, String RemoteAddress, Int32 PollID, Int32 ThreadIconID, Int32 ParentThreadID, Boolean ProcessParseInfo, PostAction objAction) at DotNetNuke.Modules.Forum.PostConnector.SubmitPost(Int32 TabID, Config objConfig, Int32 PortalID, ForumUser objForumUser, String PostSubject, String PostBody, Int32 ForumID, Int32 ParentPostID, Int32 PostID, Boolean IsPinned, Boolean IsClosed, Boolean ReplyNotify, Int32 ThreadStatus, String Attachment, String RemoteAddress, Int32 PollID, Int32 ThreadIconID, Boolean IsQuote, Boolean ProcessParseInfo) at DotNetNuke.Modules.Forum.PostEdit.cmdSubmit_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---

I am in over my head. I really need some help. This is not good.

Thanks,

Maybe a better error message for someone with more brains than me:

Server cannot append header after HTTP headers have been sent.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: Server cannot append header after HTTP headers have been sent.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. 

Stack Trace:

[HttpException (0x80004005): Server cannot append header after HTTP headers have been sent.]
   System.Web.HttpResponse.AppendHeader(String name, String value) +2849901
   DotNetNuke.HttpModules.Compression.CompressingFilter.WriteHeaders() +51
   DotNetNuke.HttpModules.Compression.DeflateFilter.Write(Byte[] buffer, Int32 offset, Int32 count) +21
   DotNetNuke.HttpModules.Compression.WhitespaceFilter.Write(Byte[] buf, Int32 offset, Int32 count) +133
   System.Web.HttpWriter.Filter(Boolean finalFiltering) +8759619
   System.Web.HttpResponse.Flush(Boolean finalFlush) +625
   System.Web.HttpResponse.Flush() +20
   System.Web.HttpWriter.WriteUTF8ResourceString(IntPtr pv, Int32 offset, Int32 size, Boolean asciiOnly) +8652644
   System.Web.UI.HtmlTextWriter.WriteUTF8ResourceString(IntPtr pv, Int32 offset, Int32 size, Boolean fAsciiOnly) +49
   System.Web.UI.ResourceBasedLiteralControl.Render(HtmlTextWriter output) +42
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
   System.Web.UI.Page.Render(HtmlTextWriter writer) +29
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266