Some memos leaked by Diebold Election Systems revealed problems with their software and unethical (and illegal) behaviour by them.
This is a direct recording electronic (DRE) system.
As such, the result cannot be verified (as with the Irish system), but it uses open source software.
Some bugs were found by people who reviewed the source code.
The Netherlands uses the same (Nedap) voting machine as the proposed Irish system, but with different software.