Program jumps forward on recordings and when playing a program from the start rather than live

Does anyone suffer from programs jumping forward or to the end when playing from the start rather than live. Also jumps forward when playing recorded programs. Have now had 6 replacements boxes in a 6 week period. A couple of the replacements had either noises hard drive. Faulty power lights or other issues, and to give virgin their dues they have replaced all of them without complaint. Big problem is they have all had this same issue and when talking with virgin techs they have no idea as to the cause. Have seen several other comments with similar issues, has anyone found a solution.

must say as friendly as all virgin staff are, and their telephone manner is always very polite, ( if I can understand them) as their accents can be quite strong. They just stick with the list of answers they are given and seem unable to think outside of the box, which means most problems never really get solved if they are outside of their remit.

would love to change supplier but have limited choice in my area and seems most companies are just the same.