Reading the International Herald Tribune (basically select articles from the NYTimes) here in Essaouira, Morocco, I stumbled across two informative articles that give some background to the Uighur conflict in China instead of just blaming the violence on ethnic hatred.
Clearly, threre have been tensions between Uighurs and the Chinese state. The first article claims that, as in Tibet, the Chinese government has slowly but surely disenfranchised Uighurs from civil service positions as well as their language and religion form daily life. Not so clear is if this disenfrachisement has caused tensions to trickle down to the population level - between Uighur population and the Han population? Just because a government oppresses a group doesn't necessarily mean that the population feels and acts the same way.
This first article also does a good job at explaining, or actually giving several different possible explanations for, the spark of the violence - a brawl at a toy facotory that employed both Uighurs and Han Chinese. Some sources say it was over a silly little rumor - one that turned out to be false - about Uighur men raping a Han woman. Another explanation is that tensions arose of long days at work, little pay exacerated differences between the two groups. Chinese officials say it was because of radical outsiders who support Xinjiang separatism. Unfortunately, due to Chinese government, the real story, which can only be reached through interviewing those who participated, won't be told anytime soon.
The Chinese government is notoriously oppressive when it comes to the plight of minority groups or any dissent, opposition groups in their Empire. Their treatment of the Uighurs is nothing new or unique, says Philip Bowring in this NYTimes op-ed. The small to big difference is the religion factor, Uighurs being Muslim. But Bowring points out that regional Muslim powers who in perfect world would pressure China never will because each of them treat their own minority groups the same way.