I have a strange problem that I see when switching to the ASP.NET designer in VS2010. It doesn't happen every time but once it's happened once it continues every time until I reboot.
Basically, when I click the "Design" button/tab to switch from the HTML to the designer, the text "Requesting Data..." appears in the status bar and the mouse pointer changes to and arrow with a spinning wait indicator. When this happens, the mouse continues to work but the keyboard input starts to fail. I can usually type but can't backspace or delete and I can't cut, copy or paste. Every other application continues to function normally so it's isolated to VS2010. It's also only affecting the designer. If I hit the "Source" button/tab to go back to the HTML, everything returns to normal.
This happens on really basic pages. My pages have a master page but the master page and the normal pages only contain basic html tags and the odd ASP.NET textbox or button.