Trouble with Non-Interaction from ADHD spouse

My husband was diagnosed with ADD about 17 years ago. We have been married for 15 years and things are beginning to fall apart.Here is the current situation: my daughter (from another marriage) has a son aged 2 ½ . This little boy just adores my husband who has a hard time interacting with him. My husband is oblivious to the fact that he doesn’t really interact with him. My daughter has been angry about this in the past and I have had discussions with my husband to make hi m aware of his non-interaction and he had corrected his behavior for a while. However, over the past few months he has gone back to his old habits. I also have to note that he doesn’t really interact with me. And, of course, I have been feeling very much alone and unloved. Just recently, my daughter and grandson spent the weekend with us and my husband continued his non-interactive behavior. My daughter has had it – she became enraged that he just doesn’t pay any attention to our grandson. She has stated that she wants nothing to do with my husband and does not want her son to get hurt from his non-interaction. To me that means that they will no longer come to my house, my grandson will not stay overnight with us, and they will not spend any holidays with us. As you can imagine, I am absolutely beside myself with what has happened. Up until this time I had an extremely good releationship with my daughter but this has now ripped us apart. I told my husband what his inaction has done and he is very upset with the consequences. I love him very much but at this point I really don’t know where to turn or what to do. I understand that the non-interaction has a lot to do with his ADD. Does anyone else out there have this problem?