I know this is a slightly aged thread, but I feel that it is worth reviving momentarily to comment generally on astrology according to Edgar Cayce. Entranced, Cayce stated that the emotional aspects of man are influenced by previous sojourns in the Earth. The mental aspects are influenced by indwellings on other planes of consciousness (embodied in the physical as the planets we see). There are indicators of both of these in our natal charts if we can get the right time. Astrology is made of just these: indicators. In various readings, he stated that free will is the most powerful force in the Universe and that by living in subjection to the influences, we learn to overcome them. Elsewhere, he referred to life in the Earth as a school.
That in mind, sleeping Cayce also said that the point to be measured in astrology is the beginning of the "life clock," starting from the moment life in Earth begins. That moment, according to Cayce, is the moment of spiritual birth. Man, existing in three parts, has three births: spiritual (up to 4.5 hours before first breath), physical (the easy one), and soul birth (up to 24 hours later). The start of the clock is the first one, which gives a window of 270 minutes (67.5 degrees) backward from the first breath. This doesn't significantly bother the measured positions of astrological bodies, but it means your houses could be off by 2.25 times the width of the average house; which means that anything based on them, such as lots (parts), will be skewed in a complex way because they are complexly derived.
This is difficult to notice because many spiritual births and physical births are close enough together to render most of the same information. Then there is another percentage that seems even less accurate and some more that are just skewed in mysterious ways. If you have a track record like this, then pay very close attention to the following.
There is a simple remedy to all of this. Rectify every chart. Even if there was a stenographer waiting for the first breath, you would still have the wrong information. It's difficult to notice because there is so much variation. The statistical data provided by John Willner suggests the average distance from physical birth time to spiritual birth time to be -1h38m33s. Knowing about this window, strikingly accurate results can be obtained by a standard rectification (performed properly). Willner claims 100% accuracy using progressions with 00* 04' 00" orbs, commonly observing closer alignments coinciding with major events in life. His books are worth a read for that alone. One might try The Perfect Horoscope (1-931044-06-6). But of course, at the end of the day, there are some, which Cayce confirms, who simply are influenced less than others for various reasons. These are probably the ones that use awareness and choice, rather than worrying about the easy times to do things.