I would go to talk to NPC's and their dialog boxes would show up, and then randomly progress to the next one or close out, as if I had clicked to continue. Often it would happen too fast for me to read what the NPC said. This doesn't automatically select any of the multiple choice response dialog boxes though, but it does jump back to the first one if you sit on any of the other ones for more than a second.
I should be able to have the dialog box sit there and not move forward with the dialog until I click the box, and I should be able to stay on each multiple choice response option without it switching automatically.
To reproduce, I'd start the game and log in successfully until I'm in the world. I'd then go up to any NPC and right click on them and select talk. It brings up the dialog box and proceeds to skip ahead without my command at random intervals.
I'm not sure what Game Client Version means, but I am running the Windows 64-bit build.