BSOD. Contradicting clues?

[Hornet]

A system that have been running stable since I build it in 2010 crashed on me today. Specification is that list in my sig, 1 main display monitor hooked up to the GTX295 and an extended display hooked up to the 9800GT.

So earlier today I had a crash several minutes after bootup, the main display turned light blue and the system stop responding. However, after I rebooted the system, everything went fine.

However, just a moment ago while I was playing a video game, my system BSOD. The stop code was 3B. From Google, it seems that many are saying 3B is related to graphics? Well, so far it does look like graphics related to me.

However looking into the dump file seems to be telling me a different thing.

First I use a tool called WhoCrashed and this was the report I got.

On Thu 5/3/2012 11:51:52 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\050312-13416-01.dmp
This was probably caused by the following module: portcls.sys (portcls+0x34BF9) 
Bugcheck code: 0x3B (0xC0000005, 0xFFFFF88005106BF9, 0xFFFFF8800E680D00, 0x0)
Error: SYSTEM_SERVICE_EXCEPTION
file path: C:\Windows\system32\drivers\portcls.sys
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: Port Class (Class Driver for Port/Miniport Devices)
Bug check description: This indicates that an exception happened while executing a routine that transitions from non-privileged code to privileged code. 
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem. 
The crash took place in a standard Microsoft module. Your system configuration may be incorrect. Possibly this problem is caused by another driver on your system which cannot be identified at this time. 


On Thu 5/3/2012 11:51:52 AM GMT your computer crashed
crash dump file: C:\Windows\memory.dmp
This was probably caused by the following module: ctaud2k.sys (ctaud2k+0x78899) 
Bugcheck code: 0x3B (0xC0000005, 0xFFFFF88005106BF9, 0xFFFFF8800E680D00, 0x0)
Error: SYSTEM_SERVICE_EXCEPTION
file path: C:\Windows\system32\drivers\ctaud2k.sys
product: Creative Audio Product
company: Creative Technology Ltd
description: Creative WDM Audio Device Driver
Bug check description: This indicates that an exception happened while executing a routine that transitions from non-privileged code to privileged code. 
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem. 
A third party driver was identified as the probable root cause of this system error. It is suggested you look for an update for the following driver: ctaud2k.sys (Creative WDM Audio Device Driver, Creative Technology Ltd).

Weird.
Using another tool BlueScreenView, it shows

So its some kind of port issues? Or is it possible that a bad graphic card may trigger something else in the dump file?

I haven't change anything in my system for months now. This problem showed up today.

Thanks for any advice

 

[Dangman]

Remove the 9800GT and see if the crashes still occur. And if you have a Creative sound card, also remove that and see if the crashes still occur