I use VS2005, and you are right, it works with default intellisense turned on, but does not work with VAX only. That is why I wrote that VAX does not recognize it.
I have default intellisense turned off, because it sometimes makes wrong suggestions (and makes too much of unusable suggestions as well).
Should it work without default intellisense turned on?
I am glad this has helped, thank you for the update
We move some of the more frequently used registry settings into our options dialog, to make them easily available. We are trying to keep the number of visible options down, to stop the options dialog getting to crowded and complex. Its a balancing act to be honest.
This settings is a bit of a special case, it is often helpful, but can cause more problems than it fixes, so we are reluctant to place it into the options dialog, since we don't want to encourage the problems.