I don't think, that the detail level is the problem - I played this game on another (much older) computer a lot of times and it worked best.
I haven't downloaded the new patches yet, but I'll try soon.
Today, as the game crashed again, I received the following Log:
Operating System: Microsoft Windows XP (5.12600)
DirectX Version: 9.0 (4.09.00.0904)
Desktop Resolution: 1024x768x16
Physical Memory: 536 / 1023 MB
Virtual Memory: 1850 / 2047 MB
Winsock 2 Detected: YES
AoW2 Version: 1.20
Display Resolution: 1024x768x16
Display Mode: Full Screen
Pixel Format: 5-6-5
3D Renderer: Hardware
Display Driver: MSI NX 6200TC (NVIDIA GeForce 6200 TurboCache(TM)) (nv4_disp.dll)
Driver Version: 0.0.0.0 (4318 / 353)
Resloution Switching: On
Detail Level: Highest
Cursor Mode: Software
Sound: On
Music: On
DirectSound: On
Map: noname.ahm
Day: 28
Play Mode: Simultaneous
Connection Type: Local
Players: 4
Human Players: 1
Seated Player: 1
Current Player: 1
Combat: None
Application opened at: 9:04:02 PM
No Dropdown Icon - DriveCB - FileDlg
No Dropdown Icon - DriveCB - FileDlg
System Time Error - Restart AoW2
Application closed at: 9:13:07 PM (3 errors)
Maybe the thing with the Dropdown Icons is the problem, but I actually don't know, what that means...
I just found the following thread:
http://aow.heavengames.com/cgi-bin/forums/display.cgi?action=ct&f=27,4583,0,all
where someone had the same message, but there is no useful answer to it...