I am having difficulty conversing with NPCs when the old engine is used. Summarily, it shows the old style screen, a quick response from me (something like "You shut your mouth and hit the road.") and the dialog is dismissed.

I was attempting to engage the NPC in hopes of a party, as per the "You are not alone" quest.

Any tips, suggestions or sympathizers?

Thanks.

"You shot your mouth..." response comes when a player, instead of saying anything, presses [enter] - and this exits the converstation.
So only thing that I could think of is excess [enter] key press before the conversation screen is up. Try to come up with chat screen with real steady moves. And you could also try to use the keyboard instead of mouse when choosing chat option. Mouse clicks are in some cases interpreted as [enter] keypressess.

I did some tests and it turns out I have something triggering my keyboard interrupt all the time. This is likely causing the conversation to end prematurely.

Thanks anyways.

Or pressing Caps lock
I have a laptop so if i press caps lock for the numbers i have the message
"you shut your...."
I must press Caps before talking to someone.;.

Owch!