My middle child (4th grade) was diagnosed with APD and we've been struggling with multiplication tables for two years now. She would work on one family of facts (the six times tables) and she'd manage to memorize them with much struggle. I'd quiz her randomly throughout the day and she'd do well. Then she'd go to bed, wake up in the morning and POOF. All gone. A friend recommended "Times Tables the Fun Way" from City Creek Press, which uses computer-based pictures and stories to teach multiplication. It just about drives me bug nuts because I just do not think that way, but there is a dramatic increase in what she can remember and retain. We homeschool, so I don't know how it would integrate with regular schoolwork.
Hope that helps