Maybe it's all because... (Check out this York University study on British attitudes towards EU too.)
Ta-dah! Speculation! Conspiracy theories!
I guess the reason why radio is objective is because radio is mostly BBC or commercial channels with their focus on music and advertisements. So either you get a view independent from commercial interests in the case of BBC, or no view at all in the case of commercial radio.
Television in Britain is a mix of BBC, ITV, Channel 4 and satellite/cable/internet channels, including Sky and US channels. Assuming that the domestic channels are EU-neutral and that the satellites have an axe to grind might explain the difference from radio. I don't know if you can draw any conclusions from this, but if you mix the perception of printed press with that of radio in a 4:6-ratio, you arrive at roughly TV numbers.
Not to forget that Britain is a bit of a queer bird in the EU due to it being a secondary country in its language area, while most other EU countries have linguistic primacy, or at least the dominating country is an EU member. The possible exception to this rule is Portugal, though I don't know how much Brazilian media they see. As a result, the British media is strongly influenced by U.S. and Australian (through News Corp.) interests and opinions. And the Australians (New Zealanders even more) really don't much like the EU, ever since the CAP started screwing up their agricultural exports back in the seventies.
(The future of the English language is pretty interesting too, with the prospect of an India-dominated English language media during the latter part of the century. You could reasonably expect the percentage of English speakers in India to go up to 40% by then (given improving education) which, coupled with a 50% increase in population, would put the number of Indian English-speakers at around 500 million. Not first-language speakers though..)
Oh, where were we? Right, reasons for anti-EU sentiments. Well. There's the common political strategy of blaming the out-group, celebrating the in-group. I.e. when things go wrong, it's EU's fault, but when things go right, it's because the current ruling party of Britain is the best ruling party in the history of ruling parties and they totally rule. And btw. you should totally vote for them in the next elections. Plus it's kinda hard to get kicked out from the EU, so you can blame it for everything. It's not like it's going to go all America on your ass, ey?
Stay tuned for the next blog post where I use the amazing powers of spreadsheets to create amusing growth projections for the mid-century!