
So, I start to think what is different from Friday to today. I stumbled up on this and I can reporduce it on my laptop and my workstation:
If you close C3D 2010 with the Anotate tab activate, restart C3D, the icons are GONE! If you change to the Home tab and close and reopen - go to Annotate tab, it is there.

So, I tried it with all the tabs and it seems like all of them do that.
So - until a fix or workaround is avaialble, remember to switch your tab to HOME before you shut down. EDIT - Thanks to Murph, another workaround is to go to a new workspace and then go back to the previous one and your Labels & Tables will be back. And to give further credit - this was discussed in the beta forum but I guess I either forgot about it or overlooked it.