Every rifle needs cleaning, an AK based weapon is a rifle, therefore it needs cleaning. Some will go longer between cleanings than others, but they still need cleaned occasionaly. I am not as retentive about cleaning my AKs as I am other weapons I own, but I do clean them from time to time.
I have seen AKs jam, in several different enviorments, it is actually not a rare occurnence by any means. There are legends and myths and more than a few BS soldiers stories about AKs that never need cleaned and never jam, but the truth is that they are as prone to failure as any other complex machine built in third world sweatshops.
I am not trying to convince you that Aks are anything other than the most reliable weapons ever made, they are no doubt about it. However they are not the invincible maintanence free death rays that so many people imagine they are.