Election experts estimate that paperless electronic machines were used by about 30 percent of voters nationwide in 2006.

Federal technology experts concluded late last year that paperless touch-screen machines could not be secured from tampering.

Some states had bought early versions of the paperless machines before the 2000 recount, and one of them, New Mexico, switched last year to optical scanners.

In the last year or so, at least 27 states have adopted measures requiring a paper trail, which has often involved replacing paperless touch-screen machines with ones that have a printer attached.

Many of the paperless machines were bought in a rush to overhaul the voting system after the disputed presidential election in 2000, which was marred by hanging chads.

But many states replaced them with paperless touch-screen machines that require voters to accept on faith that the reported vote totals accurately reflect the votes cast.

In February, Florida election officials announced that experts had concluded that poor ballot design, not the paperless machines' hardware, had been at fault.

The machines were replaced within hours, she said, and since her county uses optical scan machines rather than paperless machines, voters were able to deposit paper ballots into a ballot box until replacements arrived.

Still, the difficulty in resolving these complaints has helped fuel a drive in Congress to ban the paperless machines.

But on a paperless machine like the iVotronic, a recount is purely digital it consists of nothing but removing the flash memory inside the machine and hitting "print" again.