Rocky relations between Pakistan and the USA

A useful summary of Pakistan-American relations just published by the Congressional Research Service  notes that bilateral distrust has 'peaked' since the death of Osama bin Laden, with some members of Congress openly calling for significant reductions in US aid to Pakistan.
Relations between the two countries have certainly come under pressure in 2011, with the Raymond Davis affair, the murder of Punjab governor Salman Taseer and minorities minister Shahbaz Bhatti, the revelation that Osama bin Laden had been living in the heart of a Pakistani military cantonment for several years, controversy over US drone strikes and a general cooling of relations between the CIA and the ISI, Pakistan's intelligence service. 
In addition, as Pakistan's relations with the US have deteriorated, it has moved closer than ever before to China, with private companies recently signing contracts worth $15 billion, along with $20 billion-worth of government-to-government deals.
In March, the US summed up its relations with Pakistan by stating "Progress in our relationship with Pakistan over the last year has been substantial, but uneven", although there had been significant progress in combating al-Qaeda in the region. Despite these deep reservations, on 18 March, Hillary Clinton certified that Pakistan had made progress on ceasing support to extremist and terrorist groups. However, the outlook for the rest of 2011 is deemed to be poor.