Tiscali and Router

My Netgear DG834G (V2) router has been working fine for the first week I
have had it and been connected to Tiscali broadband. Nonetheless, during the
past week, the "i" light has started flashing amber. I have read the
userguide for the router and it states that this is some sort of testing
light on the ADSL line.

I have contacted Tiscali who state there is no problem. Now it has worked
for a week now with no problems and this flashing light only started
yesterday and lasted two hours and then service was fine again. According to
my comp, there is 54Mbps being transferred, however it won't open pages.

Any advice?