Another possible solution. Shut down Xfire. It's been known to have incompatibility Xtrap, causing potential lag. Tell me if it helps.
And a temporary solution for your lag problems in Elderine, or any crowded place is the Shift+Z function. Though you won't be able to access vending shops, it'll improve your frame rate.
Report back if anything's worked for you.
That error would still be mighty helpful
