Grouped line graph annotation rows are not exported to annotation file

If the example annotation file included in the jalview help documentation is imported onto the example feredoxin alignment, and then the annotation is exported again, the result is an annotation file which includes only the first of each group annotation rows, and an invalid 'COMBINE' statement that only includes one annotation row label (there must be at least two).

e.g.
JALVIEW_ANNOTATION
LINE_GRAPH Green Values 1.1|2.2|1.3|3.4|0.7|1.4|3.3|2.2|2.1|-1.1|3.2
LINE_GRAPH Red Values 2.1|3.2|1.3|-1.4|5.5|1.4|1.3|4.2|-1.1|1.1|3.2
COLOUR Red Values 255,0,0
COLOUR Green Values green
COMBINE Green Values Red Values

becomes
JALVIEW_ANNOTATION
LINE_GRAPH Green Values 1.1|2.2|1.3|3.4|0.7|1.4|3.3|2.2|2.1|-1.1|3.2
COLOUR Green Values green
COMBINE Green Values