Shillas,
I have found the problem, it was with your provider Datapacket.com. It in sydney, and also Amsterdam . It has been used for spam and brute force attacks. I have unblocked the provider, but some of their IP ranges will still trigger. You may need to clear the cache again, but you should be good to go now.
It did take a bit of sleuthing to sort the problem..
Bodo,
I dont know why your problem pops up, but my research seems to suggest a problem on your end. I dont know what browser / puter system you are using so cant help more