To check these claims, I did some quick regression analyses of the referenda results to see if there are any statistical anomalies in counties with different types of voting machines. Ohio uses four different types of voting machines: the Diebold AccuVote, optical scan, electronic, and punch cards. In addition to these variables, I also controlled for the percentage vote for Kerry in the county, the percentage of whites in the county, and voter turnout in the county. Results were weighted for the total number of registered voters in the county. Here are the results for each of the 5 propositions on the ballot. Statistically significant variables (p<.05) are marked with a *:
Measure 1: Bond Package
Measure 2: Vote By Mail
Measure 3: Contribution Limits
Measure 4: Redistricting
Measure 5: Secretary of State
For Measure 1, counties with the AccuVote system did have a lower percentage of yes votes (compared to punch machines, the excluded variable) and this difference is statistically significant, but this was a business-sponsored bond measure supported by the Republican Taft administration. If the AccuVotes were rigged, it's highly unlikely that they would have been rigged in a manner to hurt Measure 1.
With Measure 2, there was no statistically significant impact for any machine type.
For Measures 3, 4 and 5, all three machine variables are statistically significant, but the coefficients are positive, indicating that each of these machines actually had higher levels of yes votes than punch card systems. This result runs counter to the fraud allegations.
This is, of course, a quick and dirty analysis, but nonetheless, there doesn't seem to be any evidence to support allegations of vote fraud in the 2005 Ohio election.