We are holding documents in the default document library (VPP) and we have modified the FileSummary.config so that we can store extra information, e.g. effective date.  All well and good.  However, often we would add modified versions to a file and we would want to hold extra information, again effective date in the example above, against that version.  But this does not appear to be possible.  Has anybody come across this before and found a solution?