Below are some advices from election integrity experts at TrueVote.us, StandingForVoters.org and VotersUnite.org:
* Get the machine's serial number, if possible.
* Call over a poll supervisor to observe the problem.
* Insist on filling out a problem report.
* Refuse to vote on that machine.
* Request that the machine be taken out of service and impounded for later forensic examination.
* Tell all the voters waiting in line exactly which machine flipped your vote (first machine from the left for instance).
* Report the problem via election integrity hotlines, twitter, and the voter suppression wiki.
* Call the county, city, and state election offices and report the problem.
* Call reporters and tell them about the problem.
Additional tips from fellow voters
Don't take anything for granted until the votes are counted. Remember that the polls might prevent Democrats--especially low-income, working class, or minority Democrats--from voting as they might believe that their votes are not needed. First thing is to be sure of where you are registered to vote. Most states have an online system through the Secretary of State's office. If you can, volunteer to help encourage people to turn up on election day, please do so.
Avoid being turned away
BRING AN ID, including proof of your registered address: billing statements in your name, your latest mortgage or rent payment, and of course a state issued ID from the DMV, a birth certificate, or passport.
VOTE EARLY! There are long lines already, but Nov. 4th will be especially problematic in places where it matters the most.
DO NOT accept a "provisional ballot". If anyone challenges you, look for a supportive poll watcher to help you. The Obama campaign and volunteer sites are flying in volunteers for this from all over the country to the swing states.
Finally, if you vote on an electronic machine, PAY CLOSE ATTENTION to the screen before you submit your vote. DO NOT VOTE THE STRAIGHT TICKET OPTION- This is proving to be problematic. Vote individual candidates. VotersUnite.org recommends that people in North Carolina avoid straight-party voting. OBAMA/BIDEN '08!