.NET 3.5 - Configuration system failed to initialize exception

In my winform app, I am trying to add a userSetting, although the error is occuring with appSettings too. When the setting is added I get an exeption thrown that says: "Configuration system failed to initialize" with a Inner Exception "Unrecognized configuration section userSetting"

Exception Details:

System.Configuration.ConfigurationErrorsException was unhandled
  Message="Configuration system failed to initialize"
  Source="System.Configuration"
  BareMessage="Configuration system failed to initialize"
  Line=0
  StackTrace:
       at System.Configuration.ConfigurationManager.PrepareConfigSystem()
       at System.Configuration.ConfigurationManager.RefreshSection(String sectionName)
       at System.Configuration.ClientSettingsStore.ReadSettings(String sectionName, Boolean isUserScoped)
       at System.Configuration.LocalFileSettingsProvider.GetPropertyValues(SettingsContext context, SettingsPropertyCollection properties)
       at System.Configuration.SettingsBase.GetPropertiesFromProvider(SettingsProvider provider)
       at System.Configuration.SettingsBase.GetPropertyValueByName(String propertyName)
       at System.Configuration.SettingsBase.get_Item(String propertyName)
       at System.Configuration.ApplicationSettingsBase.GetPropertyValue(String propertyName)
       at System.Configuration.ApplicationSettingsBase.get_Item(String propertyName)
       at Settings.get_ApplicationData() in \Properties\Settings.Designer.cs:line 41
       at Common.Initialize.IsSettingsInitialized() 
       at SurveyClient.Program.Main() 
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, C