Do you have a Synaptics trackpad driver by any chance? I had a similar issue with my Acer Netbook. The mouse pointer would randomly jump, vibrate would be a better word. It would also respond unpredictably. This would only occur in Windows 7, but no issues when running Windows 8 in my dual boot system. Re-booting my Netbook would generally fix the issue.
However, it annoyed me to no end. As the issue would return quite frequently, and an updated Synaptics driver was apparently not available? So I ended up uninstalling it, and loaded Microsoft's generic mouse drive instead. No further issues, except no longer have multi-touch gestures similar to a tablet. But never used them anyway.