I created a new account, logged into it, and yet find the
problem in it as well. Root can drag cards but user cannot,

This seems to rul out a miscoconfiguration of user.

Because I had reinstalled aisleriot and I don't see others reporting a
bug in aireriot, I do not suspect the application is brokken.

I've got Chimaera installed on another disk and so when I can take
break from work to boot it to see if the problem is found with it.
I've got Beowuld installed on a laptop, and no problem dragging
cards there. I've got Jessie intalled on an older machine and find no
problem dragging cards there either.

The problem seems in the X window system used by any account on
the one disk.

Sorry to drag this petty problem out, but it is an intellectual
challenge.

--
Haines Brown