Looks like thier only complaint was that lines were too long, which they said could "persuade" people to not come out and vote.
Washington Times - Foreign election monitors laud 'fairness' of process
Reuters - Observers Urge U.S. to Shorten Lines for Next Vote
New Zealand Herald - US elections mostly fair say observers
Washington Times - Foreign election monitors laud 'fairness' of process
Reuters - Observers Urge U.S. to Shorten Lines for Next Vote
New Zealand Herald - US elections mostly fair say observers
The Organisation for Security and Co-operation in Europe said yesterday that before the vote it had received "widespread" allegations of fraud and voter suppression, mainly among minorities, and raised concern that confidence in the system could be undermined.
However, it was unable to substantiate the allegations. It said that on election day it observed relatively few attempts to challenge a voter's eligibility, despite concerns before the vote.
....
In Ohio, which decided the winner when Bush captured its 20 electoral college votes, many people stood in line for two hours or more, and some polling stations had to remain open hours after they planned to close.
"Significant delays at the polling station are likely to deter some voters and may restrict the right to vote," the OSCE said in its preliminary report.