Hi Phil-

Sorry to hear that the preset dropdown isn't funcitoning correctly, I certainly understand that using the arrows would get tedious!

What version of Cubase are you running? The early releases of Cubase 8 on Windows had some bugs that caused this behavior in many different plugins, so I'd recommend updating to the most recent version of Cubase 8 if you can.

Additionally, you could try turning the "Always on Top"  setting off, in the Cubase plug-in preferences.

Let me know if you have further issues.

-Tom