Hi Nicolas,
I'm in UK, windoze xp. It has been OK since I mentioned it here, but two days ago, another USA forum I subscribe to, was off line for a few times, for and hour or so, but they often have problems. It doesn't appear that anyone else noticed it - not surprising, since not a terrific amount of traffic on here, so I, even if I was you, am not too concerned. Maybe it shows on the log/user statistics or whatever info. you get from your host. Immediate reload didn't work on these occasions - but as mentioned may have been a name server elsewhere, but I could access other usa sites.
(Last year, Verio got more or less took down for a day or so, due to the hurrican in Florida. I never noticed them as being off line, but they refunded a month's rental, and relocated their servers afaik.)
Best wishes,
Ray