I take ivory-tower intellectuals as the prototype of high-int low-wis. High-cha fits that mold quite well. The character is extremely articulate, using his excellent language skills for rhetorical purposes. His influence is enhanced by the evident fact that he knows what he's talking about, and also can express it very clearly. But he's got a very theoretical mindset. Everything he understands well in theory, doesn't work out so well in practice. He can make well-informed decisions when he has a chance to deliberate, but his snap decisions are often poor, because he isn't good at assessing a situation when he doesn't have time to contemplate every aspect. Also, his verbal skills aren't matched by non-verbal communications -- terrible at picking up body language, unless the character takes enough Sense Motive ranks to compensate for the low wisdom.
Think back to the best teacher you ever had. That's someone who combined intelligence (deep multifaceted understanding and analysis of the subject matter) with charisma (engaging presentation in class). That person may or may not have been absent-minded; if not, you can well imagine that (s)he was without changing what made the person such a great teacher. Now suppose that, instead of going into the teaching or academic profession, the person had decided to make a career out of exploring subterranean caverns inhabited by strange monsters.