[Lizard]

He's available 60% of the time, but he's still assigned to those tasks at 100%. In the task inspector, select the tasks with this problem (individually or all at once). Then open the task dependencies inspector. The resource will be assigned at "100% of 60%". Change this to 60%. This should fix it. (If you assign any more tasks to this resource, they will automatically be assigned at 60%.)