Redstone stops working when the chunk is inactive

How to produce:

1. Make a simple redstone pulse and active it, like following image.
2. Get enough far away from the pulse, until the chunk is unloaded.
3. Come back to the pulse, and you can find that the pulse is frozen and not working anymore, until you re-active it.

This bug is a serious obstacle to all map makers, I hope you can fix it as fast as possible, thanks!