That does happen because the admin bans groups of IP addresses to cut down on the spam, you may have fallen into one of those collectives, if you click on the contact admin he will be able to unban you, there is no malice intended, it does happen frequently, but is easily rectified.
It happened to me too, sometimes just disconnecting your router from the internet for a minute or two results in getting a different IP address and your back in, or using your mobile phone data rather than your home wifi.
It's worth registering as there are a few similarities between the zx-9r and zx-12r where they use the same components, and I've probably done a picture guide on how to check and test or fix them.