I am running SC4 Deluxe on a Pentium Dual Core, 4 GB RAM and Windows 7. The graphics card is a ATI Radeon HD 4650 with the latest drivers.
I haven't created a new region, I have just tried the tutorial. I have tried starting my own cities but the same thing happens in every one. I have no plugins what so ever. Not even NAM. The problem has been there since I installed the game on my new computer. No other problems as far as I know.
The game is fresh installed, and patched with the latest patch.