I have been told that another typical problem with the Spice machines is that the battery cover breaks. At least two persons have asked me for a replacement of the original.
When you see the design, you see that there was a ongoing "theme" in HP design: the pricinples used in that battery cover were later used in the Voyager series (at a smaller size). Even the later voyager series (with the ARM processor) that had two CR2032 batteries shared the same design clues. There is a significnat difference: the spice cover has two feet glued in - so it has support function too.
I started with HP by using a HP33c during my studies - until 1st course of engineering. The battery cover broke when the batteries grew in size after being in a drawer for several months. A pity!
Here are a couple of examples: observe the upper side. It is amazing that the Spice is so similar to both!