The first thing that popped into my mind is that your H is an introvert. Are you familiar with the Myers-Briggs Personality Type scale?
I am in introvert too, so that's why his behavior kind of resonated with me. It's not so much that I am "shy" although I can be. Essentially the difference between introverts and extroverts is how they re-charge their batteries. Introverts recharge by spending time alone -- reading, watching tv or a movie, relaxing, quiet things. Extroverts, otoh, recharge by going out and being with other people -- parties, shopping, trips, etc. I can do those things and I do enjoy them, but I find them draining.
So, if your H is an introvert, I can see where he would enjoy having his mother there to visit, yet it would be draining for him too. I'm not sure about the computer thing, unless he truly just doesn't feel like messing with it. I imagine it would mean reformating the hard drives before you give them to charity, and that would be a pain in the arse. Maybe he sees that as impinging on his recharging time on the weekends/evenings?
If he is indeed an introvert, he probably prefers to spend time with himself or just a few close friends. It's not that we introverts don't like to cultivate long term relationships; we'd rather have just a few very close friends than tons of aquaintences.
