My application works just fine until, in some unidentified conditions, it begins throwing this errors:

When these errors start appearing, they appear in all over the application, no matter the code is built using ObjectDataSource or SqlDataSource. However, apparently, if the code uses some "classic", code-behind data-binding, that code does not throw errors (they do not show in the application event log), the page is displayed but it does not contain any data....

Please HELP tracking these very strange errors !!!!!!

Here is the error log from the Event Viewer

Exception information:
    Exception type: HttpUnhandledException
    Exception message: Exception of type 'System.Web.HttpUnhandledException' was thrown.
 
Request information:
    Request URL: http://SITE/agsis/Default.aspx?tabid=1281&error=DataBinding5/7/2009 10:23:03 AMa+'System.Data.DataRowView'+does+not+contain+a+property+with+the+name+'DenumireMaterie'.
    Request path: /agsis/Default.aspx
    User host address: 299.299.299.299 ;)
    User: georgeta
    Is authenticated: True
    Authentication Type: forms
    Thread account name: NT AUTHORITY\NETWORK SERVICE
 
Thread information:
    Thread ID: 1
    Thread account name: NT AUTHORITY\NETWORK SERVICE
    Is impersonating: False
    Stack trace:    at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.errorpage_aspx.ProcessRequest(HttpContext context)
   at System.Web.HttpServerUtility.ExecuteInternal(IHttpHandler handler, TextWriter writer, Boolean preserveform, Boolean setPreviousPage, VirtualPath path, VirtualPath filePath, String physPath, Exception error, String queryStringOverride)

Here is the error log from my application:

AssemblyVersion: 04.05.01
PortalID: 18
PortalName: Stiinte Economice
UserID: 85
UserName: georgeta
ActiveTabID: 1281
ActiveTabName: Plan Invatamant
RawURL: /agsis/Default.aspx?tabid=1281&error=DataBinding%3a+'System.Data.DataRowView'+does+not+contain+a+property+with+the+name+'DenumireMaterie'.
AbsoluteURL: /agsis/Default.aspx
AbsoluteURLReferrer: http://SITE/agsis/Default.aspx?tabid=1281&ctl=Login&returnurl=%2fagsis%2fDefault.aspx%3ftabid%3d1281%26ctl%3dNotePlanSemestru%26mid%3d2801%26ID_PlanSemestru%3d518%26ID_PlanInvatamant%3d304%26ID_FC%3d206%26ID_FCforma%3d85%26ID_Domeniu%3d418%26ID_AnStudiu%3d7%26ID_Specializare%3d6522%26ID_AnUniv%3d27
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SIMBAR={8C326639-C677-4045-B6D9-F59C330790E7})
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: c56dc33e-973f-467a-a90d-2a8fc7193aec
InnerException: DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'ID_PlanInvatamant'.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Web.UI.DataBinder.GetPropertyValue
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'ID_PlanInvatamant'. ---> System.Web.HttpException: DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'ID_PlanInvatamant'. at System.Web.UI.DataBinder.GetPropertyValue(Object container, String propName) at System.Web.UI.WebControls.GridView.CreateChildControls(IEnumerable dataSource, Boolean dataBinding) at System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.GridView.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data) at System.Web.UI.WebControls.DataBoundControl.PerformSelect() at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() at System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls() at System.Web.UI.Control.EnsureChildControls() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---
Source:
Server Name: SERVER2

Thank you,
Catalin