Firefox automatically clears my history

Hi All,

My first post as usually I find the info I am looking for from all you knowledgeable guru's......enough buttering up, I need answers!...lol

For the last week or so I have had Firefox automatically changing my privacy settings to "always clear my private data when I close Firefox"

I have changed this setting back just before closing a few times now and it keeps changing itself back.

It happened after I installed and then uninstalled the "Morning Coffee" add-on.

Any ideas on what to check?

Cheers,
Matt