In the Islamic context, is there any specific teaching which instructs Muslims ' 'hate the sin, but not the sinner'?
(Apart from Dr. Tahir Ul Qadri, who I am still trying to find ut about)
It may be that the Islamic interpretation of such a saying is quite different from my own ...
Hi Glow,
Here is [excerpts of] an article in which an Imam explains how we should deal with sinners [non-Muslim sinners to be more precise] in terms of loving them, and in the process he explains that we only hate the sin and not the sinner, so this may include an insight to the answer your looking for

:
Islam is a religion of mercy, tolerance and moderation. It teaches its followers to be moderate in all fields and walks of life, in aspects of worship, in dealing with others and in interaction with members of other faiths. Being extreme in one way or another would entail going against the pristine teachings of Allah Most High and His beloved Messenger (Allah bless him & give him peace).
...neither does Islam teach its followers to have hatred for fellow human beings even if they be from another faith. The reality is that Islam teaches moderation. It allows Muslims to have a good relationship with non-Muslims but to a certain limit.
...The beloved Messenger of Allah (Allah bless him & give him peace), who was sent as a mercy for the whole of mankind, demonstrated such kindness, compassion, generosity and politeness towards non-Muslims that it is difficult to find similar examples in history.
When Makka al-Mukarrama was in the grip of famine, he personally went out to help his enemies who had made him leave his home town. At the conquest of Makka, all his enemies came under his power and control, yet he set them all free saying that not only are you being given amnesty today but rather you are also forgiven for what you have done in the past. When non-Muslim prisoners of war were presented before him, he treated them with such kindness and tenderness as one would treat his own children. His enemies inflicted upon him all sorts of injuries and pain but he never raised his hand in revenge neither did he wish ill for them, rather he would pray for their guidance. A delegation from the tribe of Banu Thaqifa (who had yet not accepted Islam) came to visit him, and was given the honour of staying in the Mosque of the Prophet, a place regarded by Muslims to be the most sacred of places. (See: Ma’arif al-Qur’an, 2/51)
Finally, one should always remember that our love, hate, respect and dislike relate to actions and not the person committing these actions. Thus, we dislike the act of disbelief (kufr) but we do not hate non-Muslims as they are also the creation of Allah, hence non-Muslims deserve the same rights as Muslims. May Allah Most High give us the ability to live a life that is in accordance with His and His beloved Messenger’s (Allah bless him & give him peace) pleasure, Ameen.
ref:
http://daruliftaa.com/question.asp?txt_QuestionID=q-09004611
Hope that helps
Peace.