Belkin and ADSL line upgrade to 1mb

Just got back from a weeks holiday and tried to go online to find it
was either very slow or didnt work. I use a Belkin wireless modem
router and it worked fine before we went on holiday. While i was away
the line has been upgraded to a 1mb line. It worked fine at the
previous speed 512k but just doesnt want to sync or it does sync then
loses it after just a miniute or two. I've even swapped Belkin boxes
because my Dad has the same box so it cant be the box.

I've tried the modem BT sent me orginally, a usb BT Voyager modem and
that works fine at the new speed.

Any ideas anyone why I'm having trouble with the Belkin equipment?

Cheers
Dan
UK

> Any ideas anyone why I'm having trouble with the Belkin equipment?

Belkin modem not as sensitive as the original BT one?