Multisite Domain Registration?

Ok I was told by a support person that my existing API key for anti-splog plugin would cover my entire multisite network in this post. So I registered my root network domain (mydomain.com) but then when I try to activate anti-splog on a sub-network or sub-site (test.mydomain.com) it still says:

"There was a problem with the API key you entered: "Your Multisite Domain is not yet registered for this API Key. You are attempting to connect from test.btdevs.com." Fix it here»"

It also says you can only register up to 10 domains. But if anti-splog is good for my entire network (every sub-site - each with it's own domain) then why is it asking me to register test.mydomain.com when I already registered mydomain.com? Also, many sub-sites will indeed have a different domain from the root domain (otherdomain.com) but yet I am told on the domain registration page that you can only register 10.

I should add that the reason for this may be that I'm using Ron and Andrea's Networks+ plugin to create sub-networks within the same multisite installation, these networks are virtual and work exactly the same as the root multisite network (same plugins, same settings, etc) and are in no way different. It is simply a way to segregate the buddypress social network from the other sub-networks.

But to anti-splog, this may look like a separate multisite installation which requires a new API key. Is there a way around this? Or to somehow activate it for sub-networks? I'm sure it would be a simply line in wp-config or something eh?

Any help? Thanks.