I think the initial problem might have been caused by IB Updater - IncrediBar
I have uninstalled this in the windows control panel and it no longer shows up in the add-ons list (in safe mode). I have also run Malwarebytes Anti-Malware, but this didn't find anything.
I am also running Avast Anti virus.
The trouble shoot information below if from running in safe mode as it doesn't stay open long enough in normal mode.