LAG !!! What's going on with the CHESS client ???

For one week or so, not all the time but very often (ie. most of the time), the chessboard client (where we play LIVE games) is very slow and take 3 or 4 seconds for each move !

Useless to say that it's very hard to stay focus and not to lose on time when playing blitz.

In the past it wasn't like that. My LAG is most of the time "green" so there shouldn't be any issue but unfortunately, it's not the case. It has simply become unplayable in blitz.

Any idea of what I should do to get the client work correctly ?

Well, in fact it seems that I'm having high LAG ...
Is there anything I can do to improve this ?
Thanks

here's my PING results. Doesn't look that bad to me ... or is it ?

http://tools.pingdom.com/ping/?target=chess.com&o=1&save=true