Step to reproduce:
1) create a new project with Java Module in IntelliJ 11.0.2
2) using the "new" action and create a html file with "HTML5 file" as kind.
3) The html file should looks like the following:
4) move the caret to any tag.
5) invoke the "Quick Doc" action (^J). it always says "no document found".
However, if a html file is created using "HTML file
" (not HTML5 file) as kind, "Quick Doc" works as expected. This file has http://www.w3.org/TR/html4/loose.dtd
FYI, In project preference, my "Schema and DTD" setting has the "Default HTML language level" set to "HTML 5".