Cannot change settings on mbox account

After updating to Oneiric, I found my local folders migrated to a new mbox account. No problem there; I'm sure there are good reasons for it. However, the mbox account has some bugs / user experience issues, and in trying to work around them, I've found that I can't change settings on this account.

The usual mechanism to do this is to use the Edit / Preferences menu item, select the account with 'Mail Accounts' selected on the left, and click edit. The account (mine is 'jim@localhost') has protocol 'mbox'.

This works fine for other protocols. For the 'mbox' protocol, the 'Apply' key has been disabled. Consequently, I can't change the settings on this account, and am left with (for example) a 'from' address that is meaningless for actually sending out e-mails.

Actually changing data doesn't affect this behaviour (it's not simply whether I've actually made a change).

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: evolution 3.1.92-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-11.18-generic 3.0.4
Uname: Linux 3.0.0-11-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu1
Architecture: amd64
CheckboxSubmission: fc2d0c1a9f7a9107c5104c45d6ee1b22
CheckboxSystem: 4ed15c40009aa6f7770f606350a390a2
Date: Tue Sep 27 21:15:41 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANGUAGE=en_CA:en
 PATH=(custom, user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: evolution
UpgradeStatus: Upgraded to oneiric on 2011-09-05 (22 days ago)