Posted 02 July 2012 - 04:26 AM
Why would there be a "penalty" for changing your documents? Penalties are for blatantly trying to "fool" search engines with tricks (and "formula" SEO).
You are at liberty to change content whenever you wish and as often as you wish, but of course there is a drawback, if you change the words found at a document URL on a frequent basis, how are search engines going to determine what that URL should be weighted for?
The document URL you are changing will ALWAYS be getting "re-evaluated", so may never appear in the indexed results, or it may "bounce" in and out of the index, so provided you are not anally retentive about expecting to see your root url (AKA the "home" page) being shown to searchers for "your most important keywords", it simply isn't a problem.
Most people (including SEO "experts") create problems for themselves then call it a "penalty" rather than consider the probabilty that they "got it wrong".