Why does htop show different CPU levels for processes than top or Activity Monitor? I installed htop through brew, real pleasure of a view compared with top.

The totals across both CPUs for top align with the sum of totals per-CPU in htop. E.g. right now I see about 40% per CPU in htop, or 80% of CPU, andtop` gives the right number.

But the individual processes are completely different. CrashPlan in top currently gives ~20%, and if I sum up all of the individual tasks in top it gets to the right total.

In htop, all of the individual tasks show 0.0%, even if the total per CPU is high. 

In sum:


CPU of individual processes in top do not equal those in htop
The sum of CPU of individual processes in htop do not equal the total CPU used in htop.


What am I misunderstanding? How do I read htop results?
Turned out to be a permissioning problem. Answer from Linux is here https://superuser.com/questions/338749/htop-isnt-returning-cpu-or-memory-usage