A blank page was generate in 0.20.5. It was OK in 0.20.4. See attachments.
Created attachment 8330 [details] files for tests and results
Created attachment 8332 [details] test and results (gz)
Looks like a case of this FAQ: http://xml.apache.org/fop/faq.html#blank-page-between-page-sequences
batch transition to closed remaining pre-FOP1.0 resolved bugs