OS Name	Microsoft Windows 7 Ultimate
Version	6.1.7601 Service Pack 1 Build 7601
Other OS Description 	Not Available
OS Manufacturer	Microsoft Corporation
System Name	D-VA-HD64
I have just finished my new computer and am trying to get it all to work.
Here are first the details of the system
System Manufacturer	Gigabyte Technology Co., Ltd.
System Model	Sniper 
System Type	x64-based PC
Processor	Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz, 3901 Mhz, 4 Core(s), 8 Logical Processor(s)
BIOS Version/Date	American Megatrends Inc. F7, 5/31/2012
SMBIOS Version	2.7
Windows Directory	C:\Windows
System Directory	C:\Windows\system32
Boot Device	\Device\HarddiskVolume1
Locale	United States
Hardware Abstraction Layer	Version = "6.1.7601.17514"
User Name	D-VA-HD64\Rob
Time Zone	Pacific Daylight Time
Installed Physical Memory (RAM)	16.0 GB
Total Physical Memory	15.0 GB
Available Physical Memory	12.5 GB
Total Virtual Memory	29.9 GB
Available Virtual Memory	26.9 GB
Page File Space	15.0 GB
Page File	C:\pagefile.sys
Name	Intel(R) HD Graphics 4000
PNP Device ID	PCI\VEN_8086&DEV_0162&SUBSYS_D0001458&REV_09\3&11583659&0&10
Adapter Type	Intel(R) HD Graphics Family, Intel Corporation compatible
Adapter Description	Intel(R) HD Graphics 4000
Adapter RAM	(1,073,741,824) bytes
Installed Drivers	igdumd64.dll,igd10umd64.dll,igd10umd64.dll,igdumd32,igd10umd32,igd10umd32
Driver Version	8.15.10.2696
INF File	oem44.inf (iIVBD0 section)
Color Planes	Not Available
Color Table Entries	4294967296
Resolution	1920 x 1080 x 50 hertz
Bits/Pixel	32
Memory Address	0xF7400000-0xF77FFFFF
Memory Address	0xD0000000-0xDFFFFFFF
I/O Port	0x0000F000-0x0000F03F
IRQ Channel	IRQ 4294967290
I/O Port	0x000003B0-0x000003BB
I/O Port	0x000003C0-0x000003DF
Memory Address	0xA0000-0xBFFFF
Driver	c:\windows\system32\drivers\igdkmd64.sys (8.15.10.2696, 14.06 MB (14,745,600 bytes), 3/20/2012 1:32 PM)
	
Name	AMD Radeon HD 7800 Series
PNP Device ID	PCI\VEN_1002&DEV_6819&SUBSYS_04311043&REV_00\4&B77C4C1&0&0008
Adapter Type	AMD Radeon Graphics Processor (0x6819), Advanced Micro Devices, Inc. compatible
Adapter Description	AMD Radeon HD 7800 Series
Adapter RAM	(2,147,483,648) bytes
Installed Drivers	aticfx64.dll,aticfx64.dll,aticfx64.dll,aticfx32,aticfx32,aticfx32,atiumd64.dll,atidxx64.dll,atidxx64.dll,atiumdag,atidxx32,atidxx32,atiumdva,atiumd6a.cap,atitmm64.dll
Driver Version	8.982.0.0
INF File	oem47.inf (ati2mtag_R575B section)
Color Planes	Not Available
Color Table Entries	4294967296
Resolution	1280 x 1024 x 75 hertz
Bits/Pixel	32
Memory Address	0xE0000000-0xEFFFFFFF
Memory Address	0xF7CC0000-0xF7CFFFFF
I/O Port	0x0000DF00-0x0000DFFF
IRQ Channel	IRQ 4294967287
Driver	c:\windows\system32\drivers\atikmpag.sys (8.14.1.6268, 360.00 KB (368,640 bytes), 7/28/2012 8:14 AM)
Here are my first observations:
I have the external recorder switched ON upon startup.
LCD TV via HDMI connected to HD7850 card.
Sound is also via this LCD monitor
Using a prerecorded video input on the decklinkduo,the image and sound is in sync upon startup from the input via Decklink  Video Capture, Audio device Decklink Audio capture. (this is the first channel)
I have also an sdi monitor on the Decklink output #2, the video is playing back but no audio.
I do not find a suitable option to make the sound work via the ExternaL
But by changing the options the program frequently stops working and generates this log:
Description:
  Stopped working
Problem signature:
  Problem Event Name:	CLR20r3
  Problem Signature 01:	vmix2012x64.exe
  Problem Signature 02:	7.5.0.35
  Problem Signature 03:	503af826
  Problem Signature 04:	vMix2012
  Problem Signature 05:	7.5.0.35
  Problem Signature 06:	503af826
  Problem Signature 07:	3f5
  Problem Signature 08:	5e
  Problem Signature 09:	System.NullReferenceException
  OS Version:	6.1.7601.2.1.0.256.1
  Locale ID:	1033
So that is the first issue/question:
how do I get sound on both HDMI and SDI output via the Deckling output no2
Then I recorded the slip with the codec Decklink MJPEG Compressor and this seems to work, no dropped frames.
However, if I want to play back this file, via add input, i get an error:
CVR
AddNewInput.CVR
The operation cannot be performed because the pins are not connected.
There seems to be no appropriate Codec available.
The file is recorded, I find in the designated folder the file at 500 mb, however it will not load and also VLC is not able to play back as it is "damaged" I can choose "Play as is" but that shows only the first frame as still, while the timeline is moving.
all this time I am running the x64 version
Then I tried the normal 32 bit vMix version: suddenly I have sound in sinc on both screens (hdmi and sdi), with minimal delay (slight echo)
Recording with Blackmagic MJPEG compressor or the 8bit MJPEG Codec does 2 things:
the sound becomes "broken" irregular, the moment the rec button is pressed, then stops completely on hdmi and sdi when rec is stopped.
Only reload of the input will correct it.
Again, the file is there, but cannot be opened, with the same error message as with the x64 version.
Then I tried to record via the multicorder and this seems to weork: the generated file also shows now a real thumbnail, instead of the VLC cone. Playback works as well, however, no sound is recorded with the image, so it seems.
VLC confirms that there is no sound within this file. 
Checking the other files that do not show a thumbnail I notice that there is broken sound, with a single first frame only. it also seems to be faster than the original.
OK, this was the first test and i hope that you can help me further with it.
Best wishes.
Rob
PS., Martin , I followed your advice and rebooted several times, that did not help. then i un installed the BMD drivers and after restart installed again. issues remain.