So it was the mouse, not Blender, that has problem

It started when I tried to use scroll wheel button to scroll and pan the 3D view on Blender, and found that it didn't work.  At first I found it was the Blender software that had problem.  And then I thought maybe it's the system mouse setting.  

Finally I found out that it's the mouse itself that had problem.  After some serious slamming, it seemed to work ok now, but it may die again.  Luckily there's replacement 3rd button simulation in Blender, or maybe I should just buy another mouse.