They are certainly related - they are about the credibility of IMDB's movie rating score, however they are not duplicates in my opinion..
One is about the general credibility of the score, e.g. is a movies rated 7.0 objectively better than a movie rated 6.0.
The second relates to a specific technique or even 'urban legend' of a technique that might be used by movie marketing types to boost the score of specific movies. If this were true, and actually possible - it would clearly be a factor to undermine the credibility of the rating system. However if its not true, or even if the overall averaging of the effect against thousands of other general users means the effect is small - then it still leaves the first more general question completely valid (if not that interesting).