I remember coming across a similar error from GCC about casting from a const double pointer to a single pointer void and it said (I believe) something about having to have each cast having to be valid.  I think it was implying something like that if you have 

const void **p

you have to cast that as

(void *)(const void *)p

I will see if I can find that message and/or I can find out more about this cast problem in the Windows compiler.