I have two 32sII calculators and they have both had this problem. One of them still does.
When the first one first started exhibiting the problem, I found that I was able to get it to work by "handling" the body - twisting and bending the entire calculator a bit. That would make it work for a few days at most.
Eventually I did take it apart (as described in the post). I found that a little bit of pressure on the circuit board would fix the problem. I never did remove the circuit board but instead I placed a makeup remover sponge (something like ) This ) over the board and put the cover back on. The sponge was about 5mm thick and a very dense highly compressible foam. It provided just enough even pressure on the circuit board to keep the calculator working. It has been more than a year now and it still works fine.
I just popped the calculator closed. Even though the posts had been drilled/snapped, there is still enough friction that it holds shut by itself. I originally intended to use it for a couple of months, see if it still worked and then glue the posts. However, it has never opened by itself, even with the extra resistance of the sponge I inserted, and so I see no reason to glue it.
The approach above did not work with my second calculator. Neither did the twisting and bending. So, I took the whole thing apart as described in the post. I was not however able to get the polyetheline tape specified (because of environmental laws it is not available in California and the companies I tried to order it from will not ship it here). I tried several substitutes but did not have good luck. The calculator is still in several pieces scattered on my desk.