ASP.NET - EventMappingSettingsCollection bug on Contains method

Recently, while digging on ASP.NET 2.0 Health Monitoring I found a bug in the EventMappingSettingsCollection.Contains class method.

I was trying to check if an event mapping already exists but every time I try it the following exception was thrown:

System.NullReferenceException was unhandled by user code
  Message="Object reference not set to an instance of an object."
  Source="System.Web"
  StackTrace:
       at System.Web.Configuration.EventMappingSettingsCollection.GetElementKey(ConfigurationElement element)
       at System.Configuration.ConfigurationElementCollection.GetElementKeyInternal(ConfigurationElement element)
       at System.Configuration.ConfigurationElementCollection.BaseIndexOf(ConfigurationElement element)
       at System.Web.Configuration.EventMappingSettingsCollection.IndexOf(String name)
       at System.Web.Configuration.EventMappingSettingsCollection.Contains(String name)

I opened a bug in connect, so, if you think this is important go there and vote.

And if you think this one is not a common error ... well ... this is the second bug I found regarding Contains method from a collection class.