There seems to be a regression since May 15, 2011 when MappedEnum's buildDisplayList() was updated from

enum.map(a => (a.id, a.toString)).toList

to

enum.values.map(a => (a.id, a.toString)).toList

with commit description 'Fix deprecation for 2.9 compliance'.

Unfortunately, values.map does not keep the original order of items in enum, and thus rendering MappedEnum via toForm() (which uses buildDisplayList) will result in a select (drop down control) where items are not ordered like they are ordered in original Enumeration.

Simple fixes could be:

enum.values.toSeq.map(a => (a.id, a.toString)).toList

or

enum.values.toList.map(a => (a.id, a.toString))

Original thread referencing the commit, related discussion in scala-user list, and example fixes given above:
https://groups.google.com/d/topic/liftweb/DmEof5Zr1v8/discussion