I don't think he's asking 
for too much!  You should emphatically demand your data vendor keeps the 
data fully up-to-date with stock splits, reverse splits (consolidations), 
dilutions due to de-mergers/spin-offs, capital returns, name changes, symbol 
changes, code changes, listed exchange changes (eg AMEX -> NYSE) 
and delistings.  Without such regular maintenance your database 
rapidly will become riddled with errors.
 
> Most data sources are a minefield of inconsistent 
data filled
> with missing splits or splits where 
> none have 
occurred, missed distributions, etc.  
 
This part I agree with - most data sources are very 
poor.  
 
There's a world of difference between data vendors that 
live, eat and breathe accurate data and those that just go through the motions 
in providing "reasonably accurate" data.  The worst part is you usually 
have to pay in both time and money to find it out.
 
Best regards,
Richard 
Dale.
Norgate Investor Services
- Premium quality Stock, Futures and 
Foreign Exchange Data for
  markets in Australia, Asia, Canada, Europe, 
UK & USA -