i just noticed your location. i have the answer for you and you'll be quite pleased (i hope).

if you on the ADSL network via BT's IPStream and DataStream then you'll be pleased to know that it is NOT YOUR FAULT.

The problem is actually 2 fold;

1) BT were having a network wide problem pretty much all day yesterday. BT usually state on their status page the exchanges and phone numbers affected. But this announcement was as general as you can get;

20 December 2006
01:07 PM
Network problem
We are aware of a network problem which may be affecting access to the internet in certain areas. Our engineers are working to resolve the problem. We apologise for any inconvenience this may cause.

Now that problem was been recorded as being resolved and all should be ok.

I was having exactly the same problem last night.

2) Here is also possible explanation, but more generalised. With the recent round of BT upgrading their exchanges for 8mbit (got my upgrade for free woot). There have been reports that people are getting frequent drops in connection, especially during the 10 day upgrade period when the exchange trys to work out what the max stable speed is for you. The problems are actually mirroring what happened around this time last year when we got our round of 2mbit upgrades. Things got ironed out over about 2-3 weeks.

So sit back. Have a cup of tea and relax.