Observed with version 4:4.6~20101025.1189387-1maemo1.1188357 . 0) Prepare a mail account with two folder, one containing mails the other being empty. 1) Look at the folder containing mails. Interact with the groups if you like (e.g. collapse). 2) Swith to the folder without mails. You will still the groups and the grouped mails. Depending on the amount of mails and interaction, You will be able to see "No messages in this folder" only when scrolling in the list. You will not be able to read (touch) an email from this view, though. The expected behaviour would show an empty list for an empty folder. Otoh, this bug can come handy sometimes.
I can't reproduce this with snapshots 20101105.1193208-1maemo.1193066. Works fine with local folders and imap. Please re-test.
version: 20101202-1202744-1maemo1 I cannot reproduce the problem with this version.