Okay, solution found. Apologies to the friendly folk who tried to help, as it turns out it wasnt an Avast issue.
After further investigating about being a member of a domain, i discovered that the Security Centre is disabled by default. So, you're probably wondering how I could mistake that with an AV problem?
Unfortunately, Windows' idea of 'disabling the security centre' is to still have access to it, and make it look like its all peachy keen, it just doesnt give any _specific_ information. To get an idea of what i'm talking about, open it up, take a look. Mentally delete everything between the 'Security Essentials' paragraph, and the 'Manage Security Settings for:' section. Thats what its 'disabled' state is, hence my confusion.
So, to conclude, if anyone else has this issue, its easily resolved.
1) Make sure you are an administrator on the machine you want to enable it on
2) goto Start -> Run. type in 'gpedit.msc' (minus the '' marks), hit enter/click 'Ok'
3) Go to Local Computer Policy -> Computer Configuration -> Administrative Templates -> Windows Components -> Securitry Centre. Double click on 'Turn on Security Centre (Domain PCs only). Select 'Enabled'. Click Ok.
4) Close, reboot. Done. When you open the security centre, it'll actually contain useful information.
Thanks again for all the support
Cheers,
Aaron