Ok, I had a second so took a look.
For some reason (perhaps the version of xmlto is new or has a bug) the
temp directory was not empty so the rmdir command failed. The
remaining file was an empty .proc file that looks to be created by
xmlto.
I created a quick patch and also downloaded the latest 2.0 version.
SRPM:
http://dl.dropbox.com/u/34775202/dvdstyler/dvdstyler-2.0-1.fc15.src.rpm
RPM (x86_64):
http://dl.dropbox.com/u/34775202/dvdstyler/dvdstyler-2.0-1.fc15.x86_64.rpm
A bug should be opened[1] for this so the maintainer can fix it officially.
Richard
[1]
https://bugzilla.rpmfusion.org/