suddenly unable to receive messages from friends

[snowstar]

Adium 1.5.9
Mac OS X 10.6.9

I have been using adium on the macbook with no issues.

two days ago, i started having the following issue:
i am able to send messages, which my friends are able to receive
however, i am unable to receive messages from them.
from their end, they are able to send messages with no error signs.

i have tried re-installing adium and re-booting my macbook.
what else can i do?
i hope someone can help me. everything was working perfectly up to 2 days ago.

thank you

[Robby]

Which chat service is this with?