We currently make use of Raspberry Pi with your RS232 shields in a few of our products and this is likely to continue for at least another year. However, recently we have been encountering an issue. The new model of Raspberry Pi, the B+, has solved a few problems for us and so we have moved over to using it going forward. However, your shield made use of the old Raspberry Pi “mounting holes” to help physically secure the shield. These holes are no longer present on the B+. It is simply not an option for us to not have some kind of physical bracing of your shield.
I have examined this problem from a few different angles and attempted to 3D print some braces that might work but in the end, I fell that the best solution is for the board to be redesigned in order to take advantage of the Raspberry Pi’s new mounting holes. This can be achieved by extending your board about 7.3mm on the DB9 connector side of the board and adding at least one mounting hole in the corner that would be near the USB power connector on the Pi. I believe that just one hole there, where a standoff can be used between the Pi and your shield should be sufficient for our purposes.