I was debugging a app from our product support team where a customer’s ASP.Net app was hanging. The way we solved their problem was by putting the application name in their web.conifg. This is a little known feature (aka undocumented) that can cause you some pain. If you are seeing this problem you will need to add a key in your appSettings of your config file named Microsoft.Practices.EnterpriseLibrary.Configuration.ConfigurationManager.ApplicationName and you should be good. You can put any name you want and when you get messages in the Event Log you will get that name as the name of the application. The offending code can be found in the file PerformanceCounterInstances.cs in the project Common at line 81.
No interestingly enough , someone just posted the same thing plus a little more on the GDN site here. This is a good read and I congratulate them for being so thorough.