Centos guest goes "aborted" after clean shutdown.

[HQnet]

Hi there,

I have installed VirtualBox 4.3.30 r101610 onto a Windows 2008 x64 server in order to run Centos 6.6 x64 as a proxy server.
I opted for the 4.3x branch only because I have used it in the past and thought I rather not risk it with the new and maybe-not-so-settled 5x branch

What is happening is that every time I power off and restart the guest machine it fails to boot and gets marked as "Aborted".

Tips I´ve found here and there and didn´t help so far include removing "aborted=true" from the config file and disabling USB function (audio was disabled to begin with).
I´ve only managed to get the VM back up by using a backup of the .vbox file or re-creating the whole VM using the same virtual hard drive.
I am using vmdk as disc format for compatibility reasons, but it is a clean install.

I am attaching a log file hoping it is the correct one, the VM is running now so I am guessing this one corresponds to this morning´s incident.

Any comments will be appreciated,

Thank you.
HQ.