CP8 playback pauses

Good evening everyone,
I’ve experienced a bug in Cubase Pro 8, latest version, for the past few days : short pauses during playback. They’re approximately 1 second long, happen quite often but randomly (not on a specific part of the track), even on new projects (the CPU isn’t saturated).

I’ve just updated CP8 to the latest version, but I don’t know if it is related since I hadn’t really been producing for the past few months.

Any idea where this bug might come from ?
Thanks in advance.