I have been typing messages and thread replies when the mouse suddenly starts to dance about and what I have written disappears.
Does anyone have any suggestions about what is happening?
Need more information. Is it a conventional rollerball mouse? Does it need cleaning? Have you tried unistalling and re-installing it? Updating the driver? What OS and browser are you using? Have you recently run a malware scan?
You're using a laptop and your sleeve is on the pad thingy?