Fieldsets not rendering properly

The Bootstrap module does not render fieldsets correctly. For example, if editing node content that lies within a fieldset the legend (title) does not appear and the field data is pushed way over to the right. Before the last update fieldsets were rendered ok with minor tweaks required but now I have to do major structural work to get my sites usable again. Seems to be related to display: block css in some way.

Any help with this would be very much appreciated.