Thanks for confirmation @ReubenHood. I no longer have the problem, at least for now. Most of the times that I tried the woohoo was at the end of the day, so I decided to try it in the middle of the day, and that did seem to work. They woohooed, then slept without getting up immediately. Unfortunately, after that I could not get them to woohoo at all. They would propose the woohoo, do the woohoo happy dance, the poof, the action disappeared from the action window.
I upgraded their bed and was pleasantly surprised by the improvement energy, but still no woohoo. Another sim was now using their old bed. When i upgraded that bed, woohoo started working again for the couple. They woohoo, then one or both of them got up, but they dont switch places, which IMHO is still a bug.
So this problem may or may not be related to the patch, but they did switch beds the first time running after the patch.
There is obviously a problem with objects and sims behavior which seems worse after the patch. It bothers me that EA/Maxis added to the problem by adding ghosts to the game without solving the problems that exist. It does not bode well for the future stability of the game.