Visual Studio 2010 IntelliSense doesn't select a default value - it just marks it

I have a pretty annoying problem with the IntelliSense in Visual Studio 2010:

Every now and then (but not always - just out of my control) the Intellisense engine chooses to "mark" an option, instead of actually selecting it. This means that instead of typing e n Enter to access the default option starting with "En...", I have to type e n down Enter.

Usually it works like this for a while, and then, suddenly, the behavior I want is back. My conclusion is that there is some option somewhere that is set automatically, and that I don't know how to control.

How do I make sure that the default option is always selected, and not just "marked"?

For reference: This is Visual Studio 2010 RC, with CodeRush Xpress 10.1.

Try Ctrl-Alt-Space.

found that on Connect, and seems to work for me

It can also be changed by going to Edit -> IntelliSense -> ToggleCompletionMode

I had the same problem, but find pressing TAB always selects the default selection.

For completeness, this option has a toggle button up on the toolbar:

Its visual status will tell you which completion mode is currently selected.