Just in-case this may help someone.

It seems that the position of the memory in you PC can be an issue.

I have no way to explain this but after weeks of either no playback or poor playback and 3 different BD drives i can now watch BD discs.

some specs.

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System Information
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Time of this report: 1/13/2011, 00:59:05
Machine name: SERVER
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600) (7600.win7_gdr.100618-1621)
Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: M56S-S3
BIOS: Award Modular BIOS v6.00PG
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 5200+ (2 CPUs), ~2.7GHz
Memory: 6144MB RAM
Available OS Memory: 6142MB RAM
Page File: 2133MB used, 10149MB 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: 6.01.7600.16385 32bit Unicode

Display Devices
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Card name: ATI Radeon HD 5670
Manufacturer: ATI Technologies Inc.
Chip type: ATI display adapter (0x68D
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_68D8&SUBSYS_21D91458&REV_00
Display Memory: 3827 MB
Dedicated Memory: 1012 MB
Shared Memory: 2815 MB
Current Mode: 1360 x 768 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: PIONEER_PDP
Monitor Id: PIO00BD
Native Mode: 1360 x 768(p) (60.015Hz)
Output Type: HDMI

Driver File Version: 8.17.0010.1059 (English)
Driver Version: 8.801.0.0
DDI Version: 10.1
Driver Model: WDDM 1.1
Driver Attributes: Final Retail

so as you can see the set up is very capable.

the story.
Purchased a Samsung SH-B083 playback was poor but it did. (stutter and pauses) returned it and got an LG CH10L no play back just locked up. would not play.
Find out a Bios update was needed for the graphics card do that and every other update and no change.

Now cant return the LG drive as I am in a different country.... buy another Samsung SH-B083. fit the LG to may other PC. and it works fine!

spec

System Information
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Time of this report: 1/13/2011, 02:21:05
Machine name: NICKLOUSE-PC
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600) (7600.win7_gdr.100618-1621)
Language: English (Regional Setting: English)
System Manufacturer: Advent
System Model: QC6003
BIOS: BIOS Date: 03/13/08 17:38:29 Ver: 08.00.10
Processor: Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz (4 CPUs), ~2.3GHz
Memory: 6144MB RAM
Available OS Memory: 6042MB RAM
Page File: 2798MB used, 9284MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11

graphics

Display Devices
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Card name: Intel(R) G45/G43 Express Chipset
Manufacturer: Intel Corporation
Chip type: Intel(R) 4 Series Express Chipset Family
DAC type: Internal
Device Key: Enum\PCI\VEN_8086&DEV_2E22&SUBSYS_50028086&REV_03
Display Memory: 1695 MB
Dedicated Memory: 64 MB
Shared Memory: 1631 MB
Current Mode: 1680 x 1050 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: L200WJ
Monitor Id: GSM4E6E
Native Mode: 1680 x 1050(p) (59.883Hz)
Output Type: DVI
Driver Name: igdumd64.dll,igd10umd64.dll,igdumdx32,igd10umd32
Driver File Version: 8.15.0010.2202 (English)
Driver Version: 8.15.10.2202
DDI Version: 10
Driver Model: WDDM 1.1
Driver Attributes: Final Retail

But while in there I saw something that made me look at my media PC.

the Media PC had the memory cards in a different configuration.

initially the first pair of slots had 2 1Gb cards in and the second had 2 2Gb cards in.

so using the same memory I swapped them over. Pair 1 now has the 2 2Gb cards and pair 2 has the 2 1Gb cards and the BDs play! (except Avatar first release).

I have spoken to a few people and we can not see how this could have "fixed" this as it should not make any difference.

Michael any ideas?