Unable to write REG_DWORD using 32 bit program on 64 bit Windows 8.1

[fireymerlin]

I'm using Lua for Windows (version 5.1)
I'm able to read/write string values.
I can read REG_DWORD values from the registry.
I cannot write REG_DWORD values to the registry.
I'm using:
key:set_value('keyname', KeyValue,winapi.REG_DWORD)
where KeyValue is an whole number, like 23
I've tried using a string, '23', which also did not work.