whenever i attack in any 1.8 version my hotbar slot goes somewhere else instead of my wepon

Put the summary of the bug you're having here

*What I expected to happen was...:*to fight with my sword
Describe what you thought should happen here
strike with my sword
What actually happened was...:
Describe what happened here
my hotbar changed slots
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...get a item selected
3. ...use it on people until it happens after sevral tries and by using i mean hitting with