Steps to reproduce: - Highlight a message - Press A to archive, or D to delete Expected: message vanishes immediately; subsequent message loaded near-instantaneously in message pane Actual: message vanishes from thread pane immediately. Message header vanishes from message pane, causing message content to jump up the page. Subsequent message loads with header, causing message content area to jump down again, perhaps a different distance (depending on number of header fields). The fact that I can see this at all is a bug; my messages are 1-2k, there is no reason Thunderbird should not be able to load them faster than I can notice. But given that I can see it, the behaviour should be: message pane and header blank out immediately, but without changing size; when new message is ready, content and metadata load and any size changes happen. At no point should the message header disappear completely. Gerv

(In reply to Gervase Markham [:gerv] from comment #0) > Actual: (snip) > causing message content to jump up the page. > causing message content area to jump down again, perhaps a different distance > (depending on number of header fields). What phenomenon do you call "content jump up/jump down"? Header pane height/number of rows is changed according to number of header fields currently shown at header pane? (e.g. previous one has CC:, but next one doesn't have CC:) Independent/sequential showing of header pane, content pane, attachment pane could be observed by simple mail selection change, and slowness in it produced phenomenon like next in attachment pane(Bug 533499, bug 612279, bug 538803). although current mail has attachments, attachment was not shown. although current mail has no attachment, attachments of previous mail was shown. if IMAP/offline-use=off, "partial attachments" was also observed. It looked "attachments is displayed even after next mail display starts". It needs very quick mail switch to see phenomenon, and "delete a mail" is known as a very simple/easy way to force very quick mail switch. We could'nt observe mismatch of display between header pane and content pane because mail itself was not so large although non-displayable attachments were large, but small time lag between header pane and content pane was observed several times in test. I think phenomenon/problem you reported is root cause of above problems in attachment pane. And, it may be relevant to pheomenon reported to some bugs like next; - Even if no mail is selected any more, previously viewed mail is still displayed. It looks that message pane is not cleared. - Displayed mail is different from highlighten mail at thread pane. It looks that message pane is not cleared and current mail display fails.

Setting dependency of "attachment pane" related bugs, for ease of trackig and problem analysis.

(In reply to WADA from comment #1) > What phenomenon do you call "content jump up/jump down"? The header pane (the grey bit) disappears entirely. Therefore, the message content (the white bit) "jumps up" to fill the space. When the header pane reappears, the content returns to roughly its original position (but perhaps slightly different, if number of header rows is different). Gerv