Lets get out facts straight then.
Can You enter habbo rooms now?
If not is it constant or random times?
have you contacted habbo UK about this?
If so what did they say?
Anything else i need to know to help you?
My first answer would be its a glitch and just to restart habbo uk if it isn't constant but maybe it is your internet running to slow/not haveing to capasity to home habbo UK. Please conside both of these points