Running VF04 system extract document correctly sorted by date:
19.07.2014
21.07.2014
27.07.2014
I process through "Collective billing document" function and it create following documents:
00000001 21.07.2014
00000002 27.07.2014
00000003 19.07.2014
Note that the error is random, normally the system creates invoices sorted by date, sometimes it happen that the date sort is not respected...