Sorry for this 'bump' but i wonder if there are general issues with stable connections between modules. I have many littlebits modules, used mainly for demonstrations and without any additional mounting - just the magnetic snaps.
With brand new modules, the connections usually seem satisfactory as long as the bits are on a flat surface. combinations over 3 or 4 bits soon become problematic, but at least if the modules line up, they connect OK.
I am now about 3 or 4 months after first use. Most modules have seen adult and demo use only, but have not been used for may be a month. I am finding that most modules no longer connect reliably. Often, there is no response at all from output bits to the control input. Wriggling the bits eventually gets the required response, but the connections seem very fragile and unstable. This is not related to snaps becoming disconnected from the circuit boards. It is just the connection between modules. The gold-plated snap contacts easily get blocked with eraser swarf and can easily bend inside the snap so they no longer spring in and out correctly. I have some fibre-glass cleaning pencils used for contact cleaning but again I am worried about any debris getting stuck in the connector.
Given that a very high proportion of my modules have become far less reliable in such a short period of gentle use, I wonder how other users are getting along with theirs.