Line synced but no Internet ??

Lost my Internet a few days ago with ADSL24 on the Murphx package.
I had to reboot the router a few times to change settings but on the last reboot no connection not even an Amber light on my Netgear DG 834PN.Tried a router reset but no joy.
Tried a brand new netgear dg834 but just a solid Amber light no connection it just sticks on LCP allowed to come up but no authentication.Even tried an old green frog modem but the same problem.
I've used several different cables all working before and plugged into the bt master socket.
ADSL24 support say the line is showing as synced at their end and want to send an engineer to investigate.Has anyone else had this before and what could the cause be ?
BTW phone line is fine no noise problems.

ah so I am not the only one then. Get this from time to time. and starting to get fed up of it. thinking of moving. When you get this, do one of the following in this order:
* reboot of router
* turn off router for 20-30mins then reboot
* ring and and raise a call, they kick something and all burts into life

They reckon theres a fault on the line somewhere so a BT engineer is coming out tomorrow to investigate.