Sometimes Microsoft Visual Studio 2008 (SP1) might lock down either in Solution Explorer or when you try editing ASPX file. All mouse clicks will be followed by Windows beeping sound (the one when you try to click outside the dialog window). Attempts to close VS 2008 will display a warning about waiting for a modal window.
There is one other small detail that identifies this specific problem: when Visual Studio hangs it happens to spawn a Setup process that never exits.
This setup.exe is located in the following directory:
C:\Program Files (x86)\Common Files\microsoft shared\ OFFICE12\Office Setup Controller\Setup.exe
Running the setup.exe with administrative privilegies was not of much help, but reinstalling Microsoft Office 2007 did fix the issue.
Also if you get unexpected errors in Visual Studio 2008 while closing it or switching the window layout (this happens, for example, when you start debugging), then you've probably encountered "VS 2008 Layout bug".
Clicking "Menu - Window - Reset Window Layout" could help.