Voip Buster Callended due to UNKNOWN ERROR(33)

Hi Guys
I have been usiing voip for abt 1 year without any problems. Recently
it started giving me problem like when I make a call to any destination
(Free & NOT free), call ends immediately. The error message is " call
ended (The other party ended the call due to unknown error)". follow
the link to the error in the voip website, it says "unknow error (33)".
Could any body suggest whats the problem & what needs to be done. I
wrote customer care, but NO reply. I upgraded my balance with 10Euros
recently. did any body got the same problem???

I had the same problem a month ago.
I think that our accounts are blocked. there were 9 euros in mine and as you mentioned, there is no answer for any requests

iam using justvoip iam having balance 9 euro when i call it is saying call ended due to unknown error but my friends login is working in the same computer what is the problem to my account i dont know. I charged my account through paypal. My friend topup his account through reseller.
can anyone give me the way to solve my problem