I'm having this exact problem too. I have control of the mouse cursor when I'm in the menu after loading the game, but once I select a game and go into the 3D world, I lose all mouse control. This is the same in fullscreen and windowed mode.
Some basic dxdiag info:
Code:
------------------
System Information
------------------
Time of this report: 7/12/2012, 16:58:15
Operating System: Windows 7 Professional 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120503-2030)
Language: English (Regional Setting: English)
System Manufacturer: Alienware
System Model: Aurora-R4
BIOS: BIOS Date: 02/08/12 15:27:32 Ver: 04.06.05
Processor: Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz (12 CPUs), ~3.2GHz
Memory: 8192MB RAM
Available OS Memory: 8144MB RAM
Page File: 6282MB used, 10004MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 32bit Unicode
---------------
Display Devices
---------------
Card name: AMD Radeon HD 6800 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: ATI display adapter (0x6738)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_6738&SUBSYS_00D01002&REV_00
Display Memory: 728 MB
Dedicated Memory: 1008 MB
Shared Memory: 3816 MB
Current Mode: 1680 x 1050 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: DELL E228WFP
Monitor Id: DELD015
Native Mode: 1680 x 1050(p) (59.883Hz)
Output Type: DVI
Driver Name: aticfx64.dll,aticfx64.dll,aticfx64.dll,aticfx32,aticfx32,aticfx32,atiumd64.dll,atidxx64.dll,atidxx64.dll,atiumdag,atidxx32,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver File Version: 8.17.0010.1119 (English)
Driver Version: 8.951.0.0
DDI Version: 11
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 3/8/2012 22:14:42, 958464 bytes
WHQL Logo'd: n/a
WHQL Date Stamp: n/a