Sorry you are having trouble with the DPS 2.0 Plugin! I know you’ve already rolled back but I just wanted to respond with a couple things that might cause this:
1.) If you have DPS 1.0.7.and DPS 2.0 installed simultaneously there can be unpredictable results.
2.) Make sure that DPSReflector is selected as your default sound output device in System Settings/Sound. Otherwise there will be no effect when turning DPS on/off whatsoever.
3.) Check if the Volume Boost checkbox is checked/unchecked in DPS Preferences/Settings tab. If you are used to having it on in DPS 1.x, you might miss it if it is unchecked in DPS 2.0
4.) Make sure you are selecting the same profile, although DPS 2.0 Freeware has a limited profile selection the MacBookPro Retina and some of the Cities profiles are present in both version.
Please feel free to contact me directly at firstname.lastname@example.org with any other questions.