I've had my Windows 7 32bit UAC setting to one below the default, because the dimmed desktop annoys me.
Recently I decided to clean out the crud from my 3 year old installation, and DOpus was getting a lot of access denied errors while Explorer would prompt for elevation. Playing with the @admin directive didn't work, and the toolbar button was greyed out.
All started working as they should when I put UAC back to default.
Is this normal or a bug?