Why did Adam claim he was "naked" before God when he and Eve had clothed themselves with fig leaves?

After sinning, Adam and Eve "sewed fig leaves together" and made clothing for themselves. However, when God comes into the garden and calls to Adam, Adam responds by claiming that he was afraid and that his fear came from his own nakedness. >[Genesis 3:7-10 (ESV)](http://www.biblegateway.com/passage/?search=Genesis%203:7-10&version=ESV)
> 7Then the eyes of both were opened, and they knew that they were > naked. **And they sewed fig leaves together and made themselves > loincloths.** 8And they heard the sound of the LORD God walking in the > garden in the cool of the day, and the man and his wife hid > themselves from the presence of the LORD God among the trees of the > garden. 9But the LORD God called to the man and said to him, "Where > are you?" 10And he said, "I heard the sound of you in the garden, > and I was afraid, **because I was naked**, and I hid myself."
Why does Adam claim he is still naked, even after clothing himself with the fig leaves?