One more thing - if I #undef ENABLE_NT_HID and recompile, everything seems to work fine (I will be doing a few tests soon :) ) so my previous crash is definitely connected to ENABLE_NT_HID.
What I'll do for the next snapshot is to remove the need to use the DDK to access HID by declaring the couple of functions within the source files and dynamically linking to the appropriate library. This will simplify building it in different compile environments, and also ensure that the MingW build uses HID for the Huey too. (It turns out that MingW supplies the necessary user mode DDK headers and libraries, but they needed to be allowed for, and this is not how Microsoft arranges their build environment.) Graeme Gill.