I searched the forum without success which would suggest that most UK people have PPPoA as part of their setup.
I bought this modem to use with a Time Capsule (Airport Extreme) router. Had read good reports.
I noted the PPPoA issue but it all seemed very configurable, I use OpenDNS as well, but trying to set this modem up is doing my head in.
To begin with, I was trying the 192.168 .1.1 before I noticed that my router noting 192.168.2.1 was not a mistake.
Connecting directly to my Mac allows me to bring up the GUI and put in the values for my ISP etc, but no Internet connection.
Attaching it to the Time Capsule produced even more problems and has necessitated hasty retreats.
My Ethernet showing "Disconnected" when it patently isn't, is a constant event
Luckily my ancient Netopia (Wireless disabled) has got me back after each adventure - so far.
I suspect that it may not be possible to connect with a strictly PPPoE (LLC/SNAP ISP with this modem.
I also think that some changes need to be made to my Airport Utility setup, Internet (connect using DHCP) and Network (Router mode) Off (Bridge Mode)
I notice that the new Airport Utility which came with Lion doesn't seem to be as configurable as before.
As I have spent most of the day digging the hole deeper, I would be so grateful for any suggestions.
Thank you.

Not sure if this might help clarify but I believe PPPoA is the ADSL side of the Modem PPPoE is the Ethernet side into the modem. I found this link really helpful
http://www.draytek.co.uk/support/kb_vigor100_setup.html

I've have just gone through a a similar exercise as yourself. My configuration is Vigor 120 to Airport extreme, ethernet to time capsule. Now I had similar problems with new airport utility but I got mine working as follows. Power on the airport extreme and do a factory reset, power down the airport extreme and connect to the Vigor 120 and from airport extreme ethernet to your mac. Turn on the vigor 120, Airport extreme and open the airport utility on your mac.The Airpoprt extreme will appear as Apple xxx I edited with my ISP sign in details and it seemed to configure without too much problem ( I read somewhere that you should leave the service name blank). When Ethernet connected to my Airport Extreme I could not get on to the internet but this was because the DNS address in ethernet preferences on my Mac was not set to 10.0.1.1. change that and it should bust into life. Since installing the VIgor 120 I'm seeing a 25% to 35% increase in speed.
One problem I have not yet resolved is how to get the GUI interface to display on 192.168.2.1. it just sits there waiting in Safari and eventually says server not available. So if there's a super whiz Mr Fix it out there then there are 2 of us here who could do with a hand!

Thank you..Lots to digest there.
Will start afresh tomorrow.
In my pre Draytek Vigor days I could only get the GUI of the modem up by putting Time Capsule in Bridge Mode.
I think I managed to do that by accident.
Goodness knows what would happen to your present setup if you tried that now.
Cheers