OK here is the official word about locking up and stuff.
http://www.godgames.com/games/darkstone/
Now when that probally does not help because it is kind of vauge. What OS are you running? I am taking it for granted that you are running windows something. Update to the latest version of Direct X after you have up dated you sound and video drivers. OK the link does say this but it is not easy to get that out of it. Also you might wan to run windows update and get all the patches that are there. If you want post what kind of system you have (You know video card, sound card, ram, etc.) and people on this site will let you know if they know of any problems with any of the parts. I hope this helps.