Critical Error after doing anything.

[Slabs]

Before we get started:
VB version: 4.3.0 r89960
Host: Windows 7 64bit Home Premium (yes, I'm doing this at home)
Guest: Ubuntu 12.04 LTS
After I installed the extension pack for my Virtualbox version, I got a critical error. I restored to a previous snapshot of Ubuntu, where it Ubuntu had fully installed and had just installed additional updates for miscellaneous programs in Ubuntu. Started Ubuntu up again and it worked. After restoring that snapshot, I decided that I would install guest additions, to get some sort of progress. I installed it by going to Devices>Install Guest additions and ran the virtual CD once it was mounted. Restarted Ubuntu, critical error. I restored the trusty snapshot, started it up to check if it still worked and it did. So I figured the may have had something to do with installing the guest additions like that, so I decided to use the the "HOWTO: Install Linux Guest Additions + Xorg config" (from Linux Howto and Tutorials subforum on here), but I needed access to root to follow that guide. So, I enabled root, and then restarted so I could log in as root, but of course, when I restarted I got the critical error. As before, restored snapshot, and no error. I have no clue what I'm doing wrong, I'd love some help or teaching on what I'm doing wrong/incorrectly and how to fix it. Help should be extremely appreciated.

Error Logs are attached, of course (read descriptions for which Error Logs for each problem).

Edit:
I just realized, it's after a restart. Like, when I press "restart" it does something to the virtual machine and I always get a critical error afterwards, even with the seemingly stable snapshots. Clicking "shutdown" and then starting up the virtual machine from VB manager doesn't seem to give the error. Again, information on this would be extremely appreciated.
Edit2:
Seems like the critical error randomly appears now, whether I restart or shutdown.

[Perryg]

Install the new release 4.3.2 and see if the tripple faults go away.

[Slabs]

Fresh install for VirtualBox 4.3.2 r90405 and fresh Ubuntu install, still get critical error on restart right after I install Ubuntu. Error log attached, still the triple threat at the bottom. Help is still extremely welcome, since I have no clue how to fix this.

[Perryg]

Please attach your log file and information to this ticket https://www.virtualbox.org/ticket/12219