I saw that, Dodger :D
I'm glad I wasn't a juror on this 2 year trial that collapsed after the jurors went on strike. It cost the taxpayer many millions of pounds.
http://www.theguardian.com/uk/2005/mar/23/transport.constitution
Trials collapsing due to jury behaviour is not rare, unfortunately. Falling asleep during evidence, racial bias, internet research of defendants and witnesses, tweeting from the jury box, a juror complained that another juror had very bad body odour - all reasons for trials of very serious crimes to collapse. A juror who happened to be a police officer failed to mention he had been involved in the investigation of the case - trial collapsed.
There is no requirement for jurors to be able to read English, which I find worrying as much of the evidence is presented in written form.
Look at the questions the jury asked the judge during their deliberations in the Vicky Pryce trial, which had to abandoned due to the jury's inability to understand their function.
http://www.theweek.co.uk/uk-news/51625/vicky-pryce-jurors-%E2%80%93-were-they-stupid-or-just-confused
One juror preferred to listen to her iPod instead of the witness evidence:
http://www.dailymail.co.uk/news/article-467280/Facing-jail-juror-hijab-hid-MP3-player.html