>So, the question now becomes, how to get RV columns to accept NULLs? I couldn't find a way to do it for individual columns via DBSETPROP(), CURSORSETPROP() etc. but fortunately SET NULL ON seems to work globally which is good enough in my case.
>

Does NVL() work in this case? I don't know if the ODBC driver for Access will interpret that properly or not.