Need Help with MSN messanger.

Ok. sorry for the bad english in the fallowing conversation, but my friend [David] is mexican..Apparently he is having problems with MSN letting him send messages, but the person he is trying to contact cant talk to him, and as far as i know, neither one blocked the other.ill put the convo up.e Olde Cheese eater! says:
hi'
David...(brb) says:
i need your help!
ye Olde Cheese eater! says:
ok
David...(brb) says:
well i would like you can help me
David...(brb) says:
do you tricks or some related with msn messenger?
ye Olde Cheese eater! says:
Hmmm...you want some MSN add on programs?
David...(brb) says:
no, no..
David...(brb) says:
i want to know how can unblock a person
David...(brb) says:
lokk
David...(brb) says:
look
David...(brb) says:
this is the situation
David...(brb) says:
i have a friend, then one day he block me because we are tasting an aplication
ye Olde Cheese eater! says:
Yeah,ok.
David...(brb) says:
so now the problem is that i can se you online
David...(brb) says:
and i can send him messages and he can read it
David...(brb) says:
we probe this here in my cyber so the problem is
David...(brb) says:
he only recives my msgs but he can't write me..
David...(brb) says:
i appear block
ye Olde Cheese eater! says:
well,thats just not good.
David...(brb) says:
and when we try to unblock my contact nothing happend
ye Olde Cheese eater! says:
Hm...ok, so what did you do to msn? or is msn randomly acting up?
David...(brb) says:
before i can interact with him...
David...(brb) says:
and he's the only person i can't talk..
ye Olde Cheese eater! says:
*thinking*
ye Olde Cheese eater! says:
Well, he didnt block you, so thats not the problem...and your not away, so yeah..But i bet that its just msn being evil, it does this to me,sometimes..Displays a message "Message cannot be sent to all contacts", But Hmm...i dunno
ye Olde Cheese eater! says:
Im asking some friends

Please help!!!!im much obliged..