Menu Bar - AFTER Yosemite

Is anyone else having this issue?

If I plug something into one of the USB ports on my Mac 17" (After upgrading to Yosemite) my Menu Bar at the top of the desktop keeps disappearing and reappearing. The icons keep flashing on and off. This only happens when I plug something into a USB port.

It's very annoying and frustrating as my Mac now fails to fully recognise my iPhone and I am unable to sync it to my iTunes and my graphics tablet is acting weird too.

Yosemite has not been a success with me yet, it just seems to be one thing going wrong after another!

Anyone with any advice would be greatly appreciated!

Thanks!