Cannot enable one-click installs or upgrades for domain

Hi,

I am unable to Enable one-click installs or upgrades on this domain - the WPMUDev dashboard area simply responds with a message "You have already enabled your domain limit".

I suspect this is connected with the fact that I had a number of domains enabled previously - perhaps it's something simple like a domain counter not having been reset when I disabled and removed those?

Thanks
Gary