ClassCastException when generating EPS in headless mode

Attempting to generate an EPS in headless mode using current 2.8.x branch causes the following exception:

java -Djava.ext.dirs=lib -Djava.awt.headless=true -cp dist/jalview.jar jalview.bin.Jalview -nodisplay -open examples/uniref50.fa -eps tmp2.eps
Java version: 1.6.0_45
x86_64 Mac OS X 10.6.8
Jalview Version: DEVELOPMENT
DEBUG: jalview.bin.Jalview - Jalview Debugging Output Follows.
DEBUG - Jalview Debugging Output Follows.
Opening file: examples/uniref50.fa
Creating EPS file: tmp2.eps
Exception in thread "main" java.lang.ClassCastException: java.awt.FlowLayout cannot be cast to java.awt.GridLayout
at jalview.gui.AlignFrame.setProgressBar(AlignFrame.java:761)
at jalview.gui.AlignmentPanel.makeAlignmentImage(AlignmentPanel.java:1099)
at jalview.gui.AlignmentPanel.makeEPS(AlignmentPanel.java:1199)
at jalview.gui.AlignFrame.createEPS(AlignFrame.java:1202)
at jalview.bin.Jalview.main(Jalview.java:491)
macbookpro-24614:jalview_clean jimp$