Hey fellas, I think I've found the cause of for my strange renders. Over the weekend I had my computer flattened to see if that helped. Yesterday I needed to convert some materials from Corona to Vray materials so I installed a trial Corona, (oh! the irony), and imported the relevant geometry so I could convert. My renders IMMEDIATELY started to go wrong as they had previously. In the past I remember getting a 'Scene Convertor' window pop up asking me which renderer I wanted to convert my scene to? There is an option to choose Vray, which I did then I closed the window down though I never understood why this window appeared in the first place. After this window was closed down the weird renders started to happen though I'd, stupidly, never made the connection because it always seemed a legitimate 3D Max window. Anyway, the short of it is, it looks like messing around in anyway with my renderer triggers a bug in my genuine licence software. I've no idea why I'd be getting this Scene Convertor window all of a sudden, if anyone has an idea why I'd love to know. but it seems that might've been the cause. I'd like to thank you for your advice. Cheers