I have another sites, www.erakomputer.com, and it was build using Drupal 6.2. I thought Drupal 6 must be better than the previous versions so I decided to use it. But that's wrong -- perhaps until right now, we can't find contributed modules in Drupal 6 as much as in Drupal 5. For example adsense modules. Until today in Drupal site, adsense modules only available for drupal 4 and 5.
So, I decided to use a block and put manually my adsense code there.
Administrator >> Site building >> Blocks >> Add Block
Then activate the block. But it not working. The adsense code show as a text in a block.