I have two accounts set up, kolab + Local Folders. in kolab, there is Inbox (couple of mails)->folderA (0 mails)->folderB (2 mails). If switch to folderB, look at the first mail, switch back to folder view, switch back to folderA, then folderB, the previously looked up mail shows up automatically without further interaction. I expect to see the list of mails in that folder, not the "read view". It looks pretty reproducable. Happened in version 4:4.5~20100922.1178352-1maemo1.1177763 , not observed in earlier versions.
Can't reproduce here, still valid?