Folder settings reset to default after closing SimpleMail

[titanlab]

What steps will reproduce the problem?

1. Start SimpleMail. Folders in IMAP accounts are sorted with older mails at the top.
2. Select a folder from an IMAP account and open its settings, either with right mouse click on the selected folder or from program's menu "Folder --> Options..."
3. Change "Primary sort" to Date and check "Reverse". Click Ok button.
4. Click "Save Settings" in SimpleMail's "Settings" menu.

What is the expected output? What do you see instead?

Mail in the folder gets sorted with newer mail at the top. But after closing and restarting SimpleMail, changes aren't saved. That happens with every folder.

What version of SimpleMail and MorphOS are you using?

SimpleMail 1.1 beta
MorphOS 3.7

Please provide any additional information below.

Tested accounts are Yahoo Mail and GMail, both IMAP.
Also, if new mail arrives, it is listed at the top of the list in the folder, no matter if the rest is sorted with older mail at the top.