Hmmm the only different between our settings is
rpcallowip=127.0.0.1
i use
rpcallowip=*
for it.
it also doesn't work with the wildcard.
I tried it with diamond.conf and diamondcoin.conf in the -datadir folder. (both filenames appear in this thread)
currently trying to mine with a pool, but diff seems to be too high for a single i7 to warrant all this