No, the election was thouroughly audited by two sets of outside auditors - the OAS and Carter center.  No descrepancies were found.  Also, the exit poll you refer to was by a leading opposition organization.  All other exit polls (there were about 10) showed Chavez winning plus pre-election polls had him winning.  Now he polls around 70 to 80%.  Mind you these are by polling firms opposed to Chavez.

http://oilwars.blogspot.com/2005/05/candor-from-petkoff.html

http://oilwars.blogspot.com/2005_07_10_oilwars_archive.html

http://oilwars.blogspot.com/2005/07/yet-more-poll-numbers.html

The Carter center went home before paper ballots were tallied.  As I said, e-voting is not trustworthy (there, here, or anywhere).

If Chávez is so committed to democracy, pluralism and separation of powers, why does he sound like Castro and why did he try to  pack the Supreme Court (and succeed) to make it totally subservient to him?

Chávez runs a democracy like any other autocrat:  One man, one vote, one time.

No you are relying on some false information here.  The paper ballot audit was done by the Carter Center and the OAS.  They have the reports detailing it at the bottom of this page. http://www.cartercenter.org/activities/showdoc.asp?countryID=87&submenu=activities

As far as the court being subservient - it said the coup against him wasn't a coup and let everyone go.  Definitely subservient.

And it is not one vote one time.  Chavez himself has stood for election 3 times.  There were local elections just recently.  Congressional ones are in December and Presidential in 2006.  Sorry but Venezuela has more elections than just about anyplace I can think of