Quote:
Recently, it has been discovered that mousekeys can act in a different way on some keyboards and generate repeated outputs if keys are pressed simultaneously and held down. If this can happen on your keyboard, it would be best to avoid doing this so that you aren't flagged by the macro detection system. There has not yet been a clear official statement on whether this is allowed or not (it seems that it should not be allowed due to the clear violation of the one input, one output rule, however).
From the site.