I've found that moving sideways only works properly if your Turn Rate (in the Game Control panel) is set to at most 32x. If it's set to "smooth", then moving sideways is not only very slow, but you also tend to edge slightly forward or backward when you're moving sideways. On the other hand, if the turn rate is not set to "smooth", I find that the left and right arrow keys turn your party so quickly that it's virtually uncontrollable. Your party can't walk down the middle of a corridor; it ends up bouncing off the walls on either side as your try and correct its direction. That's not a problem in a corridor, but you try crossing a narrow bridge while your party's behaving like that!

You decide what you want to do. You can: < > < > < > < > (1) settle on a turn rate that suits you and put up with the problem it brings with it, or < > < > < > < > (2) go to the game control panel and change the turn rate back whenever you need to.

Me, I settled on the smooth turn rate, and I put up with the faulty sideways movement.

The problem arises because these games were designed on computers vastly slower than the ones we use now. The price of progress, I'm afraid.