Updated nvidia driver to 266.58 - helped a lot
Started using 16-bit color mode - helped a lot
A4 is now "choppy" in the inventory screens, pretty much running "normally" everywhere else, much more playable, I may end up buying this one too.
Hope that helps previous posters and anyone else with the problem... I had to hold down the [esc] key for a full 2 seconds to get out of inventory screens.
I'm still puzzled by the lag issue though, as stated earlier the hardware may be three years old, but A5 and A6 run no problem, as well as many more demanding games... just weird