Jose Huerta whose page you can find here (He has some interesting statistics about education and poverty in Venezuela in his page) has been looking at a comparison of the data from 4565 centers from the results of the 2000 Presidential vote and the recent recall referendum vote, as well as between the 1999 referendum and the 2000 Presidential vote. Essentially, you note that as usual time was working against Chavez as with each vote the anti-Chavez vote went up and the pro-Chavez vote went down. (Here is the full presentation and details in Power Point format). However, this trend stopped between 2000 and 2004, despite the fact that the time span between the two was much longer.
What is interesting about his results, is that he finds that if you look at the number of anti-Chavez votes at the municipal level, there is a high correlation between the 1999 and 2000 vote with R^2=0.9784:
But what is remarkable is that the correlation actually went UP between 2000 and 2004, with R^2 of 0.9866 at the municipal level:
which is somewhat counterintuitive given the time frame and everything that happened in Venezuela in those four years, including the new voters, changes in voting centers, migrations and political unrest.
Certainly very intriguing.