$ svnadmin dump file:///D:/svn/unattended > D:/tmp/unattended-init.dump

$ D:\svn>svndumptool-0.3.0\svndumptool.py merge \
-i unattended-init.dump \
-r svcpacks trunk/svcpacks \
-r xpcd trunk/cd-data \
-r xpcd-integrated-patches branches/integrated-patches \
-r make-iso.bat trunk/make-iso.bat \
-d trunk -d branches -d tags -d trunk/cd-data -d trunk/svcpacks -d branches/integrated-patches \
-x svcpack -x xpcd -x xpcd-integrated-patches \
-o unattended-changed.dump

$ mv unattended old-unattended

$ svnadmin create unattended

$ svnadmin load unattended < ..\tmp\unattended-changed.dump

... everything goes ok except for:

------- Committed revision 9 >>>

<<< Started new transaction, based on original revision 10
     * editing path : branches/integrated-patches/I386/DOSNET.INF ...svnadmin: File not found: transaction '9-1', path 'branches/integrated-patches/I386/DOSNET.INF'