see screen shot, I regularly got these empty folders created in appdata\local. It use to be in program data (but not daily as it is now), not anymore though. Reported that on TechNet with no feedback so far. I have no idea what generates these folders, as they’re always empty, at least they were each time I looked. They sound like registry entries.
Is this of any use
http://techqa.wordpress.com/2008/08/24/appdata-folder-in-windows-vista/
http://www.computerperformance.co.uk/vista/vista_appdata.htm
hmm… were you telling me what the appdata folder is or is for ??? ;D never mind 
anyway someone on technet just told me that programs temporarily generate empty folders like that. Not very useful as I figured that out already, but as I mentioned I only got one folder like that a day, and it’s always empty. So it must be the same program doing that every time and I don’t know which one. And why isn’t it located in the temp folder etc… I guess it doesn’t matter lol
I am also getting these folders. They shouldn’t be there.
It is not avast! causing it as I don’t currently have avast! installed.
It appears that it could be the latest version of Windows Live Messenger.