If you're using Muse Monitor, all you have to do is load the Muse Monitor - Muse Lab config file. Nothing else needs to be done in Muse Lab.
The config file sets up all the graphs and the receiving port.
When Muse Lab is loaded, there should be no flickering, or graphics glitches at all. If the Muse Lab program is not showing correctly, then I suspect that your problem will be with your local Java installation.
There is an old tutorial video here on youtube where someone loads Muse Lab. This video is of a Mac, but Muse Lab appears exactly the same on a PC. When the app loads, there is no flicker of any kind. This should be how it looks when you load it also.
Perhaps someone from Interaxon can confirm this, but to me it looks like Muse Lab was built in processing and the install folder contains a Java runtime. It's possible that on your system, your local java is being using rather than the included runtime and this may be messing it up.
I would recommend that you remove and re-install you local Java run time (with the latest version) and then if that doesn't work, remove and re-install Muse Lab.
If you still get errors after this, then I would give Interaxon tech support a call.