Visual glitch with split button


I jut acquired Cubase Elements 8, and I’m having several visual glitches with it.
For exemple, using the split button cause the timestamp to never disappear :

Has anyone ever experienced bug like this ?

By the way, I’m running Cubase Elements 8 (last update) 32bits on a Windows 8 64bits.
Graphic controller is AMD Radeon HD 7000.