The same happened to me although I was using a radeon geforce, installed my new HD6770 and ATI drivers and the game was working fine.
Then I stupidly decided to remove the drivers and now get the following:
Cities.exe has stopped working
Problem signature:
Problem Event Name: APPCRASH
Application Name: Cities.exe
Application Version: 5.0.0.59127
Application Timestamp: 54dc75a7
Fault Module Name: ntdll.dll
Fault Module Version: 6.1.7601.18247
Fault Module Timestamp: 521eaf24
Exception Code: c0000005
Exception Offset: 0000000000052f86
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 2057
Additional Information 1: ff24
Additional Information 2: ff246a6d815cbae559b76d95f9cd02bf
Additional Information 3: 1e30
Additional Information 4: 1e306e9f3a5a1deb1e293f58fe088230
I reinstalled ATI drivers and Windows C++ video drivers but no joy so I will email paradox support and see what they say and if I get a fix i'll let you know...