Honda: 2005 Accord Intermittent Brake Weakness, manual brakes, honda dealers

Question
Intermittently, it feels like the brakes on my 2005 Accord (88,000 miles)lose power - they feel like manual brakes.  I've had it to my local mechanic twice and to two different Honda dealers, however, none of the mechanics have witnessed the problem, there aren't any lights on my dashboard, and none of the diagnostic tests show a problem.  There's definitely a problem.  What can I do to get the problem to show itself?  

Answer
This is a tough one. It seems like the same scenario as the aches and pains I have, but if I go to the doctor I feel well.
The only advise I have is based on the frequency of the symptom. If it happens once a week, then you may need to let a technician drive the car that long.
I have not had a customer with this particular complaint on such a new Honda. Some basics to check would be the brake booster check valve and possible contaminated brake fluid.