Nimbuzz malfunction in blackberry issue

Hi,
I'm Joe. I'm a blackberry user, and I am having malfunctions with my on-board Nimbuzz application in my phone. I have recently bought this phone. I have got my all necessities set in the phone to use the internet. All the other applications that depends on the Internet runs well except for the Nimbuzz.
When I run the application, it connects with my account, but when I go in for chatting, it does not respond. I have checked everything, application access point, port settings and everything is fine.
I have even checked if my Nimbuzz account is valid, and yes I'm glad to say it is. So please, I need solution as soon as possible.
Thanks guys.
