I believe the 40 grams per meal is a myth. I do not however, have substantial proof on that. I would tend to believe that it is a myth for folks who're involved in serious exercise/lifting.
I asked that same question awhile back but received no positive evidence either way.
To digest more protein in one setting....supplement ginger root. It helps the body absorb/digest protein. Do a search for ginger root and take a look at the diet board.