If you're talking about the resetting of game options, Lee, it's not a cookie issue. (Although logic would command that it might be.) It's a confirmed bug that these game options get reset when you flush your Flash (not browser) cache. As Marioh says, "best practice" would be if all these settings were stored server-side, just as the equipment of your bag is stored server-side and not on your computer.
The main issue reported in this thread isn't a cookie issue, either, because the bug was present in all 4 browsers I tested, regardless of their different cookie collections. 