Thou shalt make sure thou art a Site Collection Administrator when running STSADM -o ActivateFeature that creates new sites or else thou art doomed to suffer painfully with Access Denied errors and half-baked sites.
On 2011-05-27. on a SharePoint 2007 SP2 project I was working on, the Farm Administrator was running a series of STSADM commands I had given her to install and activate a brand new (to the first level integration environment she was logged into) feature. The STSADM command, ActivateFeature, consistently failed for her yet never once failed for me in my development environment.
It turned out, the actions of the FeatureActivated event were such that they could only be performed by a Site Collection Administrator. Farm Administrator privileges were not enough. Once she made herself a Site Collection Administrator in addition to being a Farm Administrator, the feature activated with zero errors.