Every time I see this issue, it's with laptops where the trackpad on the laptop is still enabled, even though an external mouse is being used. A lot of times people rest their palm on the trackpad, and that registers as a mouse click.
If your external keyboard happens to have its own trackpad, then make very sure that you are not accidentally touching this in any way.
I have an Acer Aspire 5920g laptop running Windows 7. To make typing easier I have been using a bluetooth mouse and keyboard.
When I type in I find that the cursor jumps all over the place and the characters I am typing get inserted where ever the cursor has decided to jump to.
I have watched what is happening and there have been no physical shocks to the keyboard or mouse to make the cursor jump.
It makes typing a nightmare and touch typing impossible.
What can I do to stop this strange behaviour?

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