The player database contains quite a few mistakes about player heights and weights. For instance, it lists Robin Söderling as being 190 cm and having 81 kg. But according to the official ATP site, he is 193 cm and has 87 kg - quite a significant difference. Most mistakes are more minor than that, with players being listed as 1 cm too short or 1 kg too little. Novak Djokovic really is 188 cm, while the database gives 187 cm. And so on.
I could go over some of the more famous players, adjust their values to the ones given on the official ATP site, and send you a corrected Players.ATP.ini file, if you like?