One of the most often asked questions about Nabokov is was he a paedophile?
In his essay "On a Book Entitled Lolita" he claims that he had no other purpose in writing such a controversial novel “than to get rid of that book".

Among the main themes of Lolita are depictions of incest, child molestation, obsession, and paedophilia. There have been attempts made to determine a connection between Humbert Humbert and Nabokov. There have been a lot of theories; there is even a name given to people who study Lolita: “Dolorologists”.

Nabokov defines art in two ways. His first definition is "Art at its greatest is fantastically deceitful and complex". His second theory is, "Beauty plus pity - that is the closest we can get to a definition of art". Nabokov also claims that Lolita was his most difficult book. He said that the book was based on a theme which was “so distant, so remote” from his own emotional life that it gave him special pleasure to use his “combinational talent” to make it real.

One conjecture is that Nabokov was a victim of abuse. Many critics have been able to piece together some of Nabokov's early childhood. According to Brandon Centerwall, as a young boy Nabokov had an uncle who was a paedophile. Uncle Ruka apparently abused Nabokov as a boy, and although his parents knew of the abuse, they did nothing to stop the scandal. Uncle Ruka was Nabokov's mother's brother, who had no children of his own. When Uncle Ruka died he left his fortune to Nabokov. It was a trifle odd that a teenager was left millions, but it can be thought of as some sort of compensation for his ‘sexual services’. There are many parallels between Uncle Ruka and Nabokov, and Humbert Humbert and Lolita. The first and most obvious similarity is that Nabokov was age twelve during the escapade and Uncle Ruka was thirty-seven. Lolita was a young nymphet of twelve and Humbert Humbert was thirty-seven.

But another similarity was that Nabokov had a strange relationship with his own mother, as did Lolita with Charlotte. One critic points out that all the women in Lolita die. Humbert’s mother also died when he was very young, and then his caretaker took a turn for the worse, Charlotte was killed, and in the end Lolita died during childbirth, (the passage through life when she is to become a mother). Freud did numerous studies on the Oedipus complex, when a young boy has intimate feelings towards his mother and has a dislike to his father, or the other man in his mothers life. Although Freud's preoccupation with the Oedipus complex is subject to question, psychological evidence confirms that incestuous thoughts and feelings, largely subconscious, do play a part in human behavior. Nabokov did not keep his dislike of Sigmund Freud a secret. At the end of The Annotated Lolita, he wrote, “I detest symbols and allegories (which is due partly to my old feud with Freudian voodooism and part to my loathing of generalizations devised by literary mythists and sociologists)”. He said, in an interview:

"I think he's crude, I think he's medieval, and I don't want an elderly gentleman from Vienna with an umbrella inflicting his dreams upon me. I don't have the dreams that he discusses in his books. I don't see umbrellas in my dreams. Or balloons.

"I think that the creative artist is an exile in his study, in his bedroom, in the circle of his lamplight. He's quite alone there; he's the lone wolf. As soon as he's together with somebody else he shares his secret, he shares his mystery, he shares his God with somebody else."

It can be argued that Nabokov's strong dislike for Freud and his theories may have something to do with the fact that his secrets were being uncovered, analyzed and even explained. Nabokov did not like these analyses of his writing, or his personal life. However, as icicle pointed out, Freud was incompatible with Nabokov's whole world view and since, as we all know, since Freud's theories have been widely discredited, the whole "repressed secrets" train of thought doesn't necessarily work.

sources included http://www.coh.arizona.edu/inst/eng102-lolita/essays/emang.htm and http://www.nytimes.com/books/97/03/02/lifetimes/nab-v-freud.html