[graf_von_anonym]

Alright, you can't ping the remote servers. I can't pretend to any great familiarity with Ubuntu, but I'll talk about that subsequent to some questions:

Can you ping the default gateway being assigned to your computer (or the router to which it is connected)? Can you ping the modem? Can you ping the loopback address?

It's unlikely that you're being limited to port 80 alone, given the general rule I will also outline below, at least by something external. Do you connect through a router? Have you tried bypassing it?

Finally, in this questioning phase, can you access newsgroups? You may get some assistance from 2nd line who monitor the Virgin Media support newsgroup. While they too are limited by what is known as a "support scope", they have greater leeway to stray.

So, the two things I said I would mention:

Call-centres are in in India and other places because there is a ready supply of labour that is cheap and the populace speak English (or an approximation thereof), for the same reason that there are call centres in places like Wales, Scotland, or the Midlands. They are almost all out-sourced to as a cost-saving measure. They have targets to deliver, and these almost all revolve around handling calls in a specific way. Because of perception-warping artifacts of management nonsense like Six Sigma and ISO9000 these almost all relate to physical measurements: volume of calls handled; average call length; staff hours lost to illness, indolence, training; and perhaps some arbitary box-ticking or hoop-jumping exercise that masquerades as 'quality'.

This focus on technical support as an extruded product rather than a process has a number of advantages - it makes it very easy to stamp out "solutions" for most needs. It falls apart at the edge cases, however, for the same reason that some house are furnished differently - think of your floor, for a second. Call-centres, as an industry, want to be in the industry of selling rugs, not fitting carpets. The latter takes time, skill, attention, and engenders a certain measure of waste. It is also an exact fit. Given the choice between cheap but imperfect and difficult but expensive, people and organisations will usually choose the former. Even more frustrating, however, is that "support scope" gives companies like Virgin the option of limiting the rooms they will furnish to those that are specifically proportioned rectangles. This is why you are being stymied - you are going to people who have only been asked to sell you rugs and asking them to help you fit a carpet. It doesn't work very well at Ikea, but some of them might be able to advise you if you are lucky, and you're in the same situation here.

Secondly, and this is worth putting in bold, Virgin don't care. I mean, yes, they want you to be happy. They are an Internet Service Provider, and they'll do their utmost to provide you with web access (and I am aware of the distinction, though many who work for Virgin may not be). What they won't do is things like block ports, or filter specific protocols, or deny access to specific websites (Internet Watch Foundation aside). It's not that they can't, or couldn't, but that it's effort. Almost every difficulty with Virgin is caused by a solution implemented not because it was best but because it was either easiest or cheapest, and often these are mutually exclusive, but the latter will tend to win. The same is true of almost every large organisation driven by trying to service a high level of debt and shareholder demands. That extends to your experience of customer support I'm afraid. I appreciate that it's cold comfort, indeed, I don't even intend it to be a comfort to you. I'm merely explaining, not excusing.