An examination board has been criticised for mix-ups which left some Students with the wrong marks, and others studying a course with no textbook.

The Oxford, Cambridge and RSA (OCR) board has apologised for the marks error but denied responsibility for the missing book.

The cases follow complaints against OCR by Magdalen College School, Oxford, after the board lost 24 exam scripts completed by students at the school, and by Peers School, Littlemore, after marking mistakes cost student Joe Swarbrick a place this year at Cambridge University.

Students at Abingdon and Witney College claimed the board used them as guinea pigs, after grading errors resulted in their being awarded the wrong marks for A-level modules.

Four students at the college received the wrong grades after marks for papers were lost because of a computer error. The mistakes came to light when students raised the alarm. They have yet to receive their certificates.

Tom Waterhouse, an A-level media studies student at the college's Abingdon campus, said OCR had sent him an incorrect results sheet last August, in which the board claimed he had not taken part in one of the three modules of his course.

He said: "This was false, and an inquiry was made into this inaccuracy. I am yet to receive my real results.

"How much more do we, as students, have to put up with? Being used as guinea pigs for a new system, record levels of exam stress, increased pressure to succeed, and now being denied our just reward for our hard work."

The college's director of marketing, Steve Billcliffe, said: "Tom is justified in complaining and I sympathise with the anxieties he's had."

At Burford School, OCR has been accused of incompetence after setting a course for which there is no textbook. The exam board denies the allegation.

Fourteen A-level physics students were left without a course book for their module in materials physics. The book was to have been released by Cambridge University Press at the beginning of last year, but the publication date was repeatedly pushed back.

It is now set to be released in April -- after the end of the course.

Chris Hollingdale, head boy at Burford School, said: "I am outraged at the inadequacies of the examining body. Although the book has been put on the web, it lacks diagrams and pictures essential for a total understanding of the subject."

Chris, who was also a victim of the much-publicised Edexcel AS-level maths paper fiasco -- which featured an unanswerable question -- said: "I am wondering how the Government can stand by and let this happen when it is our future at stake."

The school's head of science, Andy Blower, said: "We have been dead unlucky in that we picked a module for which the textbook isn't ready.

"They are saying the book will be out in April, which is ridiculously late, as teaching will have finished, and the students will be revising.

"It is pretty difficult to study without a textbook. We can just about manage, but it affects students' confidence in the board, and also their confidence in me.

"It is down to the incompetence of the whole system. The Government keeps changing everything and exam boards have to respond. No-one can keep up."

Burford School headteacher Patrick Sanders said: "I have a certain amount of sympathy with examination boards as they have been put under enormous pressure, and mistakes are inevitable given the number of qualifications and papers.

"However, if a textbook is needed to support the syllabus, the exam board has an obligation to make sure it's available."

An OCR spokesman said the board was investigating the delays at Abingdon and Witney College.

He said: "OCR dealt with nearly 200,000 candidate entries in August. However, regardless of the original mistake, the error at OCR should not have happened. We apologise to the candidates. We are taking steps to improve the training of staff to prevent this type of incident happening again."

But he denied the board was at fault over the lack of a textbook for its physics module at Burford School.

He said: "OCR is responsible for the design and production of the syllabus and examinations. We are also responsible for marking, producing the results and issuing the certificates.

"We make every effort to supply our own materials to assist teachers. Dozens of publishers produce books on syllabus subjects. A few choose to produce specific texts aimed at specific syllabuses.

"It would be quite wrong of us to specify the use of one particular book, or to hold up the introduction of a syllabus until an independent company had produced a specific text.

"Teachers want to choose their own books from the wide range that is available on this subject."

A spokesman for the Government's Department of Education and Skills, said: "Any allegations that have been made against an exam board must be looked into by the Qualifications and Curriculum Authority, which is the independent regulator."

She denied the mistakes were a result of Government pressure on exam boards. She added: "In general, we have found that when mistakes have been made by examining bodies in processing papers, the mistakes are of an administrative nature, and are not due to undue pressure caused by AS-levels."