More information.
I "upgraded" to 6.0-01 (what it was, just did an upgrade in place to try to flush out any inconsistancies with the default install) which didnt seem to fix the issue.
Googling for it has said stuff about installing relevent modules, which I am a little hessitant to do due to this being a live server with bucketloads of users.
I am in the process of removing all contribs one by one in order of their install to make sure they are not the culprit (though the system has been running forever with these contribs) and will once again update you all to the issue.
Patrick