Is your AWS security group configured correctly to allow traffic on port 9990?.
Bloody good question.
I'd switched off the firewall (temporarily) in centos (which strangely just stopped all access!) but didn't know it was also configurable at the aws level.
Presumably there's a group for 'general access' (i.e. Any web based user rocks up at the i.p. Address) that I need to open up that port (just for testing). Would I be looking for something with a 0.0.0.0 mask?
Excellent answer, thanks very much indeed.