Hi cody,
Here the steps to debug a designer:
1. In you designer's project open project propeties.
2. In the properties dialog select 'Configuration Properties | Debugging
3. Change 'Debug Mode' to 'Program' (by default it is 'Project')
4. Hit 'Apply' (I believe that is bug in VS.NET)
5. In the 'Start Application' navigate to and select 'devenv.exe'
application. My VS.NET by default opens the file dialog in its folder.
Anyways you can find it in "<VS.NET folder>\Common7\IDE folder
6 Hit OK
From now on when you start the project for debugging it will start a new
instance of the IDE in the new IDE open a test project (that is the project
where you going to use the component with the designer you want to debug).
In the first IDE you can set break points in the designer's code. It is
might be somehow confusing which IDE is the debuger and which is the second,
but wach for the 'start' button. On the first IDE it should be gray. This is
the same if you attach to already running process but is more convenient.