Extra protection against async aborts
Version 0.14 changed the default PSR for new threads to disable async aborts, to match how most (all?) machines run the main RISC OS thread. However there are a few other places in the code which set the PSR to constant values and could allow async aborts to slip in.
Track down the places where constant PSR values are being used and make sure the A bit gets set, to avoid async aborts becoming enabled.