Windows Messenger chat and sending/receiving files

Hi,

I've looked through and I have seen the same type of
problem regarding being able to send files and not
receive them. However, earlier today my friend could
click start talking and we could chat. I rebooted after a
while as I needed to defrag. Now I can send the request
and chat, but if he does it will not connect. Have
checked the firewall and there is nothing wrong there.
Also the same is with the files, I can send the file but
cannot receive them. Is there any other reason as this
is happening. We are both using Windows Messenger
4.7.2009.

Thanks in advance