About twenty minutes into any Civ IV game I play, the cursor disappears/freezes, but an invisible cursor can still control the game. When I exit out, Windows is in this permanent state of invisible cursor, and I have to restart. How could I fix this?

Also, I'm having issues with the ingame BG music not playing, unless in diplomatic talks or zoomed into a city. And, lastly, when starting a game, the loading takes somewhere around 15 minutes to get into the game. My computer exceeds all of the listed recommended stats, so what can I do?