in testcase http://iso.qa.ubuntu.com/qatracker/milestones/302/builds/52742/testcases/1498/results for ubuntustudio at step 6: Select the 'Upgrade Upgrade' option, There is no upgrade option.
ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: ubiquity 2.15.16 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 3.11.0-2.1-lowlatency 3.11.0-rc5
Uname: Linux 3.11.0-2-lowlatency i686
ApportVersion: 2.12.1-0ubuntu3
Architecture: i386
CasperVersion: 1.336
Date: Thu Sep 5 02:07:36 2013
InstallCmdLine: noprompt cdrom-detect/try-usb=true file=/cdrom/preseed/ubuntustudio.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash --
LiveMediaBuild: Ubuntu-Studio 13.10 "Saucy Salamander" - Alpha i386 (20130902)
MarkForUpload: True
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)
just in case the attached logs do not show this, raring was installed on a USB drive and there are various installs on the internal drive, but no raring. (11.04, 12.04 and 13.10)