Nested Master Pages and Intellisense
Despite my strict mantra, "I don't do websites", here I am working on a plain old website. But thanks to www.templatemonster.com and ASP.NET master pages, it's going pretty quickly.
But here's an odd thing with master pages. I have nested master pages and when I get to a content page (or another master page) that's two levels deep or higher, VS2005 no longer recognizes the <asp> controls in my HTML. They work just fine but the IDE marks them as errors ("not a known element") and they don't show up in intellisense...
...unless I open the master page(s) in the IDE (doesn't matter if it's design mode or source mode). In which case, all is right with the world again.