Ich habe wahrscheinlich die selbe Grafikkarte, hier ein Auszug MEINER DxDiag, bei mir funktioniert unter 64 Bit Vista (nicht Win7) alles normal.
Vergleicht bitte mal! Vielleicht hilft es euch..
(Müsste mal Everest installieren um den genauen Typ zu bestimmen)
Card name: ATI Radeon HD 4800 Series
Manufacturer: ATI Technologies Inc.
Chip type: ATI Radeon Graphics Processor (0x9440)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_9440&SUBSYS_22671787&REV_00
Display Memory: 2809 MB
Dedicated Memory: 1018 MB
Shared Memory: 1791 MB
Current Mode: 1152 x 864 (32 bit) (60Hz)
Monitor: PnP-Monitor (Standard)
Driver Name: atiumdag,atidxx32,atidxx64.dll,atiumdva,atiumd64.dll,atiumd6a.cap,atitmm64.dll
Driver Version: 8.14.0010.0662 (English)
DDI Version: 10.1
Driver Attributes: Final Retail
Driver Date/Size: 4/29/2009 03:52:02, 3082752 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: {D7B71EE2-D700-11CF-A176-6D02A1C2C535}
Vendor ID: 0x1002
Device ID: 0x9440
SubSys ID: 0x22671787
--------------------------------------------------------------------------
SEINE:
Card name: ATI Radeon HD 4800 Series
Manufacturer: ATI Technologies Inc.
Chip type: ATI Radeon Graphics Processor (0x9440)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_9440&SUBSYS_080110B0&REV_00
Display Memory: 1787 MB
Dedicated Memory: 1020 MB
Shared Memory: 767 MB
Current Mode: 1280 x 1024 (32 bit) (60Hz)
Monitor Name: PnP-Monitor (Standard)
Monitor Model: SyncMaster
Monitor Id: SAM018F
Native Mode: 1280 x 1024(p) (60.020Hz)
Output Type: HD15
Driver Name: atiumd64.dll,atidxx64.dll,atiumdag,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver File Version: 8.14.0010.0662 (English)
Driver Version: 8.612.0.0
DDI Version: 10.1
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 4/29/2009 03:47:28, 4006400 bytes
WHQL Logo'd: n/a
WHQL Date Stamp: n/a
Device Identifier: {D7B71EE2-D700-11CF-9671-0B28A1C2C535}
Vendor ID: 0x1002
Device ID: 0x9440
SubSys ID: 0x080110B0