It disappears then appears again after some time. I have found no clear pattern, but it seems that sometimes it disappears after clicking it twice with a pause of about second. Though I've also seen it disappearing on its own.
It reappears in a few seconds, so it isn't a major problem, but it is annoying a bit.
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: clementine 1.2.0+dfsg-2build1
ProcVersionSignature: Ubuntu 3.13.0-18.38-generic 3.13.6
Uname: Linux 3.13.0-18-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Mar 19 21:27:59 2014
InstallationDate: Installed on 2014-03-18 (1 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140316)
SourcePackage: clementine
UpgradeStatus: No upgrade log present (probably fresh install)
Hello, I confirm this issue in the package shipped with Ubuntu (same specs as posted by Alexander) and with the development version, 1.2.2-392-g213fb2c