I have noticed for some time that auto-run on start up works usually, but not always.
Then sometimes it goes into "monitoring is active" mode, but not always.
And sometimes it drops active monitoring, but not often.
I have CC Professional v5.00.5050 (64bit) on Windows 7 Home Premium SP1, AMD A8-6600k APU with Radeon HD Graphics, 8.0GB RAM, AMD Radeon HD 8570D
I use Outpost Pro Security Suite Pro 9.1.
My settings options on Ccleaner are shown in the attached screen shots