Mostly dead since yesterday...

[#1]

...but I'm connected TO plusnet, the router has picked up PN's IP address and DNS; but no connection beyond plusnet.
Router is failing at the 'ping default gateway' phase, and I'm seeing 'PADO timeout' errors and 'LCP down' errors.
Router passes: DSL sync | ATM OAM pings | PPP server conn | ISP authentication | Test assigned IP address
Router fails: ping default gateway | ping Primary DNS | Test DNS root | NCSI
No material changes at my end, and weather 'normal' (!!); it packed up during simple browsing.
Any ideas?

[#2]

How's the connection looking now? There were a lot of disconnections yesterday, but the connection is showing stable for the last 3+ hours.

[#3]

Hi Chris,
Still falling down at 'ping default gateway' I'm afraid. 
The stable connection I suspect is just the connection *to* PN; it seems i'm not getting *through* PN to the wider world.
C.