I've noticed that when I run Classic, it forgets some of my preferences. Iirc, at one point, I had the /nc and /ns options stuck on in Classic (which I preferred.) And my hotkey bar in the lower right corner of my screen. However, after multi-clienting in Renewal a while back, (I had to shut off /nc and /ns to get one of the characters to auto-follow the other...) my Classic client "forgot" that I prefer /nc /ns on. And my hotkey bar loads up in the middle of my screen. I leave it in the top right on Renewal. I never have to move it.
On top of that, if I log into Classic, it'll auto-populate the username field with the last account I used on Renewal, even if I don't use that account on Classic. Even if I log into Classic on my main account, if I log out to character select screen, then click "cancel", it'll go back to the password screen with the same account (the last one I used on Renewal) in the username field again. I never have any of these problems with Chaos.
I've checked out the setup file for Classic (doesn't help, obviously) and have searched the forums, but couldn't find anything. Is there a way to get Classic to remember these things for me?