Observer triggers on login

Observer triggers on login if watching active redstone dust

Steps to recreate:
1) Place redstone dust
2) Place redstone torch or block next to dust to activate dust
3) Place observer to read the redstone dust
4) Place dispenser/dropper on output end of observer
5) Place 1 or more items in the dispenser/dropper
6) Log off
7) Log back on and see the dispenser/dropper has been triggered by the observer and expelled an item

I can confirm this works every time on Creative mode, on Survival i have had this happening randomly.