i get an error when trying to enable run on startup "Error saving Auto Start setting to Registry.
Attempted to perform an unathorised operation."

any ideas?

I have gotten this same message with my PC (HP notebook running Vista Home Prem). I disabled my anti-virus and my spyware protection but the issue was not resolved.

Anyone have any other ideas what may be causing it??

--Aaron

I wouldn't necessarily disable anti-malware or antivirus.
Rather set exclusions for DisplayFusion.
Your symptoms are typical of not having permission to allow changes to the Registry.
You may have to give yourself (your account) permission or elevate your permission status for Displayfusion or try and set it via an Admin account.

I'm not sure if TweakUAC will help in this case,but it will for other stuff.
Check it out at http://www.tweak-uac.com/

Pete.

PS. Since there was no followup to this post as yet,
I'm adding some other suggestions:
You could manually edit the Registry - some info here:
http://www.computerperformance.co.uk/vista/vista_registry.htm
If you have Windows Defender,I think you can control Startup entries.
Not sure if you can add.If not, the utility below will help.
Startup Manager http://cupersoft.com/content/view/44/61/

HTH
Pete.