There is a huge difference between being able to absorb information and being able to organize and write reports and develop projects.
Some things to think about:
What skills do these reports and projects draw on?
Are they working with the ability to draw conclusions from data and make testable predictions, or are they more like book reports and presentations?
Do they require a lot of handwriting or good motor skills to be successful?
Is he actually being asked to collect data that might enable him to discover something that he doesn't already know, or are these projects the kind of "experiments" that should really be called "demonstrations"?
Are they covering topics that are new to him, or material that he learned a long time ago?
The answers to these questions could tell you a lot about what his issues are with the material. It could be complete lack of challenge, or it could be that he needs practice or explicit instruction in some skill areas required for developing these work products independent of their science content (or possible lack of it).
