A constant struggle

As part of "working together" with the school, the guidance counselor is sending weekly progress reports from the teachers.  Got my first one today.  All the same, pretty much.  Behavior is good, but not doing any work.  Homework is due, not doing it.  Tests coming up, make sure he studies. It's tempting to "stick my head in the sand", but I'm tired of seeing the same old problem & not being able to solve it.  I so want to be able to trust my son when he says "my homework is done".  Unfortunately, I can't.  Argh!  It really breaks my heart.