The X Factor did not breach broadcasting rules over the way the competition was conducted, Ofcom ruled today.
The regulator received 944 complaints from viewers over last year's show, which was eventually won by Alexandra Burke.
Complaints included not being able to get through to vote, particularly in November when Austin Drage and Laura White, an early favourite to win, were booted of the ITV1 show.
Other complaints surrounded a voting re-cap last October, when the telephone number allocated to Ruth Lorenzo was incorrect, raising concerns about whether she had received all the votes intended for her.
Some people also complained that Diana Vickers was automatically put through one week, despite being too ill to perform.
Voting lines were checked before, during and after each show and checks were done with the audio message attached to each number to ensure the numbers corresponded correctly.
Those responsible for programme compliance told Ofcom that any failures would have been automatically flagged up for immediate attention.
Although lines were busy, there were no significant congestion problems found, including in the home towns of Drage and White.
Several people who complained were also found to have not dialled properly or used the number for the previous week, which had changed.
In the case of the wrong number being shown for Lorenzo when a single digit was missing, this was on the screen for fewer than five seconds.
It was also found that there was no significant change in the voter momentum for Lorenzo in the moments after the error.
Ofcom found that putting Vickers through to the next week when she was ill "presented no possibility of material harm to viewers and as such rested entirely with the broadcaster and production team".
Ofcom said: "The data available to Ofcom did not indicate shortcomings in the series design, editorial judgment or administrative and technical arrangements such that viewers' or callers' interests were abused."