hi tdpete, have you set firefox to never remember a history in the privacy section of the options or using it in a private browsing window? if so, then what you're seeing is probably the new tracking protection feature in firefox 42 with private browsing in action. however, since this totally optional, you can easily turn it off in the privacy section of the options panel: Turn off Tracking Protection

Yes, I always have the option to never remember history turned on and always use private browsing. How is the option for telling sites not to track different than using tracking protection in private windows? Basically what I gather from above is that prior to firefox 42 that you could still be tracked even using private windows. Is this correct?

private browsing mode has traditionally meant that firefox won't store any information about your browsing session locally on your device - now it is also combined with blocking tracking content on websites.

in addition: the do-not-track feature allows you to communicate your preference to not be tracked to websites, but it is up to them if they respect this and follow up on it. the new tracking protection mechanism enforces this by actively blocking connections to elements which are considered to be trackers...