Significant problems with voting machines at yesterday's US mid-term elections have been reported to watchdog groups, with thousands of voters complaining that technical flaws hampered their visit to the polls.

Common Cause, a government watchdog group, received more than 14,000 calls to its voter hotline by mid-afternoon yesterday, including hundreds of reports of "vote-flipping", where the machine's summary screen shows a different result to the one the voter wanted. The Common Cause hotline includes all kinds of voting problems, not just those with e-voting.

E-voting watchdogs saw significant problems with vote-flipping in the 2004 national election, and Verified Voting called for a national investigation then but was rebuffed, said David Dill, founder of Verified Voting and a computer science professor at Stanford University.

"Not surprisingly, we are experiencing the same problems," Dill said during a press briefing. "This kind of problem – I think it's a national disgrace."

Common Cause officials said yesterday afternoon they were seeing fewer voting problems than they did in 2004, but reports of problems could take days to surface, Dill said.

In Denver, Colorado, voters encountered queues of more than two hours because of apparent problems with a registration database. Voters there could cast their ballots at any voting location, but the rolls were apparently contained on just one overloaded database, said Pete Naismith, a spokesman for Common Cause in Colorado.

"It's the classic situation where too many cars are jammed onto one highway," he said.

The election commissioner in Johnson County, Kansas, dismissed sketchy reports that poll workers there were using hand lotion to keep voter cards from spitting out of machines. Election commissioner Brian Newby said reports to that effect had got it the wrong way round. When a poll worker has used too much hand lotion, voter cards can get stuck in the machine that recodes them, but a simple reboot fixes the problem, he said.

"I'm amazed," he said of the reports regarding hand lotion. "It's urban legend."

Other technical glitches reported yesterday include;

  • In one Indiana county, e-voting machines didn't turn on. In a second county, the machine activation cards weren't programmed properly.
  • More than 2,000 calls to Common Cause's voter hotline came from Pennsylvania. There were reports in three counties of e-voting glitches, the group said.
  • Election Protection 365 workers asked for extended voting hours because of numerous reports of machine failures and poll workers who were unable to operate voting machines. The county uses a combination of optical scan and e-voting machines, according to Verified Voting.
  • There were reports of voting machine failures in parts of Florida and Utah.