In version 1.02 of Start10 the Power button control does not function well for two of the possible options.

If I select Sleep, I get Shut down. If I select Hibernate, I get Shut down.
The other options (log off, change user, lock, etc) act as expected. 

My assumption is that the enumeration of the different Power button options does not correspond to the different Power button settings in Windows. It could also be that the language setting of Start10 versus the language of Windows is playing a role here as well.