Some folders cannot be sorted?

Owning a Mac computer for nearly year but still find a lot of glitches in daily usage. As rumored as a very user friendly system, i find it not any easier than Windows. Here is a problem which bothered me for a long time until i searched the web for solution: When open some folders in finder, the title row is fixed and cannot be sorted.

I admit it is my own fault. Played around with the MacBook Air and did a lot of customizations. The toolbar buttons are all rearranged to suit my preferences and it happened to me the "Arrange" button was removed.

To show that button again, two-finger click/right click on empty space in the toolbar, and choose "custom toolbar".

When "Arrange" is set to anything but "None", the title bar in the columns view will be fixed and no longer clickable to sort. Set to "None" and all is done.