As was eluded to at this thread: [url=http://forum.audionews.ru/We%20do%20URLs%20in%20several%20different%20ways..
http://forum.audionews.ru/viewtopic.php?t=61394]http://forum.audionews.ru/viewtopic.php?t=61394[/url], the issue has to do with RMX not being able to find an ethernet adapter en0; as I believe it uses the MAC address of the first adapter as a part of it's challenge creation.
My hackintosh had an ethernet adapter at en2 (and not en0) and the challenge code was garbage.
I edited: /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist
and editing:
<key>BSD Name</key>
<string>en2</string> >>> changed to en0
<key>IOBuiltin</key>
<false/>
<key>IOInterfaceType</key>
<integer>6</integer>
<key>IOInterfaceUnit</key>
<integer>2</integer> >>> changed to 0
enabled the network settings panel to find a 'new' adapter, en0, and the challenge then worked.
Hope that helps someone.