virtualbox.org

Your solution is no solution. You did not use the 4.3.8_RC1 ISO to install the guest additions, because the ISO file contains an installer from Feb 21 2014 which cannot be 4.3.18.
Most probably you selected "insert Guest Additions CD" from the menu some time before this and didn't remove the virtual CD.
Therefore your selecting the downloaded ISO didn't change anything because the current 4.3.18 ISO was still in the drive and you just installed the correct 4.3.18 version.

Perry I was careful when I did the GA's. And yes I realize what you are saying. But until others try it we shall never know. I suppose I could create another VM.

That was not me this time dsherman it was another user. But his reply was exactly what I expected to happen.