The finding raises questions about the Government's drive to install the devices, costing around pound;2,000 each, in every classroom so teachers can project video clips and educational games.
Researchers from Newcastle university studied 122 primary schools in six local authorities, visited lessons and interviewed teachers and pupils.
The teachers were overwhelmingly positive about interactive whiteboards.
Most expected they would raise pupils' results and 99 per cent said they had improved the children's motivation.
The children were equally keen to praise the technology. One said: "It's better than the normal whiteboard because on that all you can do is write and draw boring pictures but on (the interactive) one you can do loads of different kinds of stuff and you can play games."
The researchers found that lessons with interactive whiteboards tended to have a faster pace and that pupils would give longer answers to their teachers' questions.
In the first year of the study - 2003 - they also noticed that the schools which used them performed fractionally better than comparison schools in maths and science tests. However, in the second year there was no difference in results between the schools.
The report said the early improvement "may have been a novelty effect of some kind".
"It could be that the motivational aspects of the interactive whiteboards and the pupils' obvious enjoyment of lessons may have misled the teachers into thinking that more learning was taking place than was actually the case."
The report said that improvements gained may have been at the expense of other more effective teaching practices. There was seven-and-a-half minutes less group work in lessons with interactive whiteboards than in others.
Eight out of 10 teachers interviewed said the whiteboards added to their workload at first, although many said they had cut it in the long-term.
Pupils said that common frustrations included difficulties seeing the board on bright days or their teachers' poor technical skills. "It can get a bit annoying when she can't remember how to work it," one said.
Steve Higgins, director of Newcastle university's centre for teaching and learning, said that teachers should not be "seduced by the superficial appeal". "Schools need to work out how such a large investment can produce genuine learning benefits," he said.
Whiteboards were accused of damaging children's eyes last year after a company reported its staff had "seen stars" after installing them, but the concerns were debunked by safety experts.
Key figures in some IT firms, including Microsoft, have also questioned whether investing in the boards was sensible when teachers could produce many of the same lessons using cheaper projectors and laptops.
The Department for Education and Skills said: "Ofsted tells us that whiteboards improve the quality of teaching, enabling teachers to deliver exciting and engaging lessons to children of all ages and abilities."
The researchers' report, Embedding ICT in the Literacy and Numeracy Strategies, is at www.ncl.ac.uk
Take them away? Cause a riot
Birchley St Mary's Catholic primary in Wigan, Lancashire has more touch-interactive and pen-interactive whiteboards than teachers Sarah Neild, ICT co-ordinator: "If you tried taking them away there would be a riot. I can't imagine teaching without it now. It's not going to transform a rubbish teacher. But it makes it much easier if you're teaching something like reflection and rotation in maths because you can show it on the screen."
John Leake, headteacher: "I teach French and find the boards are a great way of making modern languages fast and visual. When you do weather and say 'nuage' you can show a moving cloud."
Jane Talbot-Davies, head of infants: "It's much better than the presentations I used to make with cards and Blu-tack, where bits always fell off. If you've got 10 minutes before assembly you can quickly bring up a literacy activity you were doing the week before. I think it has made my pupils' spelling better."
Kate Riley, aged seven: "It's really good because you can see what Miss has on her laptop. And you can play games like Charlie Chimp's Big Modelling Party, where you decide what clothes Charlie should wear at the circus and the funfair."
Elizabeth Simms, aged seven: "You can go on the internet and see lots of different websites. We've gone to the BBC website on Egypt to learn what their gods meant and to play a game where you have to choose people to build a pyramid."
Harry Smith, aged six: "We use it for loads of things like planning stories. I like moving words and pictures around. The thing I don't like is when they have to calibrate it and the sound isn't on - that's boring."