Apparently whatever update it's trying to apply is failing. Best thing to do would be to uninstall, reboot, and reinstall. That should fix whatever problem is preventing a clean update. That happens now and then in my office.
I agree with foxyshadis, I've had the same problem when an update was offered, I installed it yet I didn't get a confirmation that the installation failed. Hence the update check came back everytime I booted my computer. Removing the plugin manually solved the problem definitely.