I recently needed to set the TopLevel property for a form but intellisense didn’t indicate that this property existed. The documentation said it existed, and, indeed, it does.
However, because VS.NET's default behavior is to hide “advanced members“ for VB projects, intellisense didn't display it until I went to Tools->Options and cleared the option to “Hide Advanced Members”. This option can be found under Text Editor->Basic->General.
These aren't hidden by default for C#. I guess MS assumed “Basic“ developers don't need the “Advanced” members.