To reproduce:
1.) Open Thunar.
2.) Select the "View" menu from the menu bar.
3.) Select "View as Detailed List".
4.) Select the "Edit" menu from the menu bar.
5.) Select "Preferences".
6.) Go to the "Display" tab.
7.) Select "Icon View" under "View new folders using:"

You can open any folder or close and reopen Thunar it will always list items in "View as Detailed List" mode and ignore the setting set in preferences.
I would either expect Thunar to respect settings set in preferences or not having the specified setting under preferences if it is either way ignored.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: thunar 1.6.3-1ubuntu5
ProcVersionSignature: Ubuntu 3.13.0-45.74-generic 3.13.11-ckt13
Uname: Linux 3.13.0-45-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: XFCE
Date: Wed Feb 25 22:42:58 2015
SourcePackage: thunar
UpgradeStatus: No upgrade log present (probably fresh install)