Thanks to jimoblak
But have now managed to solve this on on my own, the machines were not my own but a client's so I only properly observed the problem today when I was physically at the machines; When I saw that the mouse also jumped a little, on occasion, it led me to alter the graphic hardware acceleration to zero! no problems any more.
Thank Goodness and greetings to all.
Hope this helps someone
Graham McHardy
Scotland.