I have tried numerous .conf files, the current one is simply the nodes you listed above:
addnode=208.72.104.70
addnode=108.20.183.67
addnode=81.56.104.39
addnode=90.190.237.233
It is located in the same directory as the Fastcoin client, which is in My Documents:
\\users\<username>\Documents\Digital currency\Fastcoin-Qt\
This is where I have all wallets installed and they all work, but it made me wonder does Fastcoin depend upon an app data install location?