Lyrics background is "transparent", making it hard to read lyrics

[pianomartin]

Thank you very much for all your quick responses.

I found the problem!

Beavis -> You were actually close to the bone, mentioning the videocard.
When I The lyrics window is displayed in the Macbook's own screen everything is perfect. However, if the lyrics window is moved to my 27" thunderbolt display the problem with "transparent" background occurs.
I don't know why this happens and I don't know how to solve it, but it's really not important, as I am not going to bring the External display with me at performances.

About the Windows issues:
I did a clean win-installation about a week ago, so it's "brand new". I didn't really change any settings in Windows, which means the Windows downloads and installs updates automatically. (which is about 72 updates or so every second day :-) ).
Is this a problem? I recall that a few years ago you had to agree that you had read and understood certain win7 settings that were to be altered before installing Hoster. I did not get any warnings about this when I installed this version. I figured that it was because Win7 had become stable enough to run smoothly.

Did MTU ever consider to create a Mac-version?! Most musicians use Mac, and it's really a lot less trouble getting Things to Work!

Anyway, thank you for all your responses.

[Beavis]

when in windows you need to see if the refresh rate changed on the external monitor. the higher the better. i dont have windows 8 in front of me right now but in windows xp its just right clicking on the desktop and going to setting, then advanced then monitor.

[pianomartin]

Wow, that solved everything.
On the internal screen I can only choose 60 Hz, on the thunderbolt display I can choose between 59 Hz and 60 Hz (not that much of a difference, though :-) )
Everything is fine now.
Thank you.