Haywire Display Dials

[mark47]

Hi, I've had an Ipsum for about 4 years, quite happy with it, good comfortable family car. The display dials have recently started behaving oddly, they suddenly show an extreme increase in both speed and rev's without any noticeable increase in engine speed, the freeze. after a few minutes the dials return to normal operation. Whilst the dials are behaving erratically the gearbox drops out of gear leaving me without drive, once the rev's drop, the gears re-engage, as you can imagine this gets quite scary when on the motorway. This happens fequently for no apparent reason. I have had the vehicle checked by a local garage but they found nothing that would cause these symptoms. has anyone else experienced this and can they suggest a cause and remedy.

Many Thanks

Mark47