Thanks Peter. Now that Firefox sits on the icon bar and does not disappear when startled I will keep it running all the time alongside of Netsurf. It helps to be using Moredesk of course because I can have a screen for each browser and quickly swap back and forward.
Just one regret. I wish had read drobe before re-downloading and re-installing Tinct, UnixLib etc in an attempt to get round the start up problem. Thanks for the solution Doug.