In case this affects others: This is to alert Mozilla Thunderbird users to a potential glitch that jumped up and bit me. I use T-bird as my email client in a way that is perhaps a bit different from other folk. My setup has IMAP accounts at uOttawa and gmail, with an outgoing smtp server at ncf.ca. At the beginning of each month, I back up the Saved and Sent messages from my primary uOttawa account by - copying Saved to local saveyymm e.g., save1202 on 2012-3-1, Sent to sentyymm. - delete IMAP server savelast and sentlast - move Saved to savelast, Sent to sentlast There are typically 400-600 msgs in a month kept in Saved, 200 in Sent. My process is to select a folder (Saved or Sent), hit Ctrl-A, then right click in the greyed out area and Copy or Move to the appropriate local or remote folder. A couple of weeks ago I discovered my save1112 was corrupted with empty headers and content for many message, or no content for some with headers. uOttawa keeps backups for 30 days, and I was able to get them to recover savelast for January. Downloaded and found similar problem, but different messages corrupt. Tried again and had better luck, but not perfect. Finally merged all my corrupt folders and used "Remove Duplicat Messages" plugin and got most back. Initial thought was flakey disk on uOttawa IMAP server, but yesterday got same problem on download and watching carefully noted that the Ctrl-A selection took up to 10 seconds, and I had started the transfer. Seems that this is the "nasty". Copying things still undergoing selection would seem to make sense, since corruption of save1112 local and savelast was different (they were different processes). So this is a warning to let the selection settle before doing a copy or move. Possibly the T-bird developers could put in a check so that user is warned, or else copy or move should be locked until selection complete. John Nash