In VS 2005, C++ Code, the tooltip is not appearing when I hover over classes or methods.
When I check VS Options / Text Editor / C/C++ / Formatting / Enable automatic Quick Info tooltips, there appears a tooltip but it is very basic and also do not show the code documentation.
If I uncheck it, the only thing that appears is a "down arrow" with a "refactoring" menu.
Note that VA X Options / Text Editor / C/C++ / Display comments from source files when available is checked, Parse all files when opening a project is checked, and Get content from Intellisense in unchecked.
The tooltip used to work on VS 2003 and it was very nice, showing the documentation for the class, function or parameter.