[imp] IMP shows mailbox as empty when sorted by date is required

[Jean-Yves Avenard]

Hello

I have a horde installation which has been working fine for several years.

I have one user with over 14,000 emails in his mailbox.

>From time to time, its inbox will show no messages "There are no
messages in this mailbox." but will still report how many newor unread
 messages in this folder.

I usually sort this issue by deleting the user preferences in the SQL database.

However, today I've been able to always reproduce that issue.

By default, IMP will sort messages by message ID and it will be able
to display all the messages.

However, if the sort order is changed in any ways, IMP will report
"There are no messages in this mailbox." and you can not change the
sorting options anymore and the inbox folder will stay forever empty.

Changing the sorting order in the Options menus have no effect whatsoever.

I have allocated 128MB to PHP in php.ini.

I can not see any error messages in any logs.

Any ideas what I could have been missing or what could be done to fix
this issue?

Thank you
Jean-Yves