The mystery is solved. I use continuous focus mode almost exclusively, and I use dynamic area focus... so there we have it.
I didn't really fret though, as I don't want beeps and lights going off anyway. Good to see it was not an error however.
>I'm not sure if you have checked the following, so here >goes... > >Regarding the AF-Assist Illuminator, there are some conditions >where it does not operate. To quote from the D700 manual (p. >290): > >The AF-assist illuminator lights when lighting is poor. AF >assist >illumination is only available when both of the following >conditions are met: >1. Single-servo autofocus is selected for focus mode (pg. >72). >2. Auto-area AF is chosen for AF-area mode (pg. 74), or >single-point or dynamic-area AF is chosen and the center >focus point is selected. > >Regarding the in-focus beep, there are also some conditions >where it will not sound. From the manual (p. 298): > >Choose High or Low to sound a beep when the self-timer is >used >or the camera focuses in single-servo autofocus (note that a >beep >will not sound if Release is selected for Custom >Setting a2 (AF-S priority selection, pg. 284). > >