As the previous posts indicated, the topic might need more definition. Like all philosophical inquiry, the idea of objectivity seeks to transcend individual condition, context, and bias in order to develop judgments and analysis that are applicable to all. This is something which is powerful in its condition as well as appealing in the idea of transcendence and reaching past individual bias or condition. If one accepts this premise, the science of sociology can be one which is almost "above" human contexts. I think this is probably where trouble arises because the fundamental condition of consciousness is one of contingency and a lack of totality. Yet, the ideal of objectivity rejects this in embracing totalizing and singular conceptions of the good.
The ideal of objectivity in sociology: giant question. My best short answer would be this: Although it may be impossible, the best way to aspire to sociological objectivity is that the societal and personal influence of the observer (sociologist) must always be taken into account.
Also, a lot of sociological theories can only be tested over time. Certain economic, cultural and national factors will contribute during the passing of history and this complexity of variables makes it difficult to make a definitive statement about direct causes and affects due to social behavior. And since, at any given time, in any given society, societal norms will change, any claim to an objective or universal (timeless) theory of sociology will tend to be a centrist interpretation. Biased by current ideologies of a society at its certain point in history. Case in point, Marxists today, while somewhat diverse, think very differently from Marxists in Karl Marx's time. This is not because of a fundamental disagreement with Karl: it's because certain events (i.e. unions) occurred which did not adhere to Karl's theory of social progress (the proletariate did not take over.)
Some sociologists will see a social conflict as abnormal, a symptom; others will see it as a normal occurence: this depends on the interpretation of the sociologist. So, the ideal of objectivity simply remains a possible goal. Even theoretical physicists rely on unproven theories, some of which will be proven, and some not. They study behavior of particles and sociologists study behavior of people. The sociologists may have a longer struggle towards objectivity because unlike particles, humans can change their minds, sometimes making them more unpredictable than quantum particles.
So, the positivist doctrine that society's progress is predictable based on observed (sense) quantitative behavior is not the bottom line. In the end, the goal of an objective science is to predict behavior. If you are a determinist (you believe that a comprehensive theory of history and society will predict all behaviors), then an objective sociological theory is near impossible, but at least it's conceivable. If you are not a determinist, an antipositivist maybe, then you concede that certain events cannot be predicted: this is a result of qualitative events, the complexity of socio-economic relations and really, the ability or free will of the individual to think outside the box of history: to do something that is not historically determined. Or, you're somewhere in the middle.
As a proactive sociologist, you might take your comprehensive theory and propose what should be done to ensure a more ethical future. Your biases may cloud your rationale and your well-intentioned sociological implementations (i.e. educational reforms like No Child Left Behind) may backfire. In the end, sociological objectivity is an ideal, but one worth striving for.
This is not a lot of go on. However, I think you are asking if sociology believes in objectivity. One of the basic points of sociology (and anthropology) is that there is no such thing as objective truth. And even if there was such a thing as objective truth, how can a person get to it? All people are biased, historically situated and very selective.
The reason why there is no objective truth is because sociology states that all societies are socially constructed by people. Therefore, societies are the product of subjective people. This is why one society differs from another. So, sociology, in the end, seeks to study, for the most part, the logic of a society.