Actually I started a couple of threads on this at sci.crypt which is about as knowledgable on encryption and computer safety as you can get. Their verdict is that computers can never be safe for vote counting and the only thing to do is go back to paper. Not surprising when you realise most of them use Windows as a base and all the vulnerabilities that are found in Windows.

If you go to Black Box Voting there's a section with 14 PDF files in chapters. Read those and you'll be horrified. There's a lot of evidence for example Chuck Hagel used his own voting machines to get in the senate and wants to run for president using them.