STR 1 Start up TB 3.1, select a msg so that you see it in msg reader preview 2 ensure you do NOT touch/hover/click/view/open the View > Zoom submenu 3 press Ctrl++ or Ctrl+- 4 click into msg preview pane and repeat 3 5 open msg in tab and repeat 3 6 open msg in window and repeat 3 7 hover over View > Zoom menu so that it pops open 8 repeat 3 where it previously didn't work Actual result 3 focus on msg: nothing 4 focus on preview: nothing 5 msg in tab: nothing 6 msg in window: zoom works fine 8 after Zoom menu has been opened/viewed: works fine everywhere, as it should Conclusion: for fixing this bug, check what happens when user opens Zoom menu. Somewhere there seems to be some code that fixes the problem and enables the zoom

hmmm, it works in -safe-mode... but I don't have very special addons

(In reply to comment #1) > hmmm, it works in -safe-mode... but I don't have very special addons Might be a theme too. What do you call "special" ?

Active addons: DOM inspector 2.0.8, German Dictionary 2.0.1, Lightning 1.0b2, XNote 2.2.0pre1. All other addons disabled, so they shouldn't do anything, right?

Lightning 1.0b2 is the culprit for this bug. Ctrl++ works right away as it should when Lightning is disabled. Ctrl++ does NOT work right away whith Lightning *enabled*; only works after viewing the View > Zoom menu. You draw your own conclusions. I don't think there are dupes, unless they don't have the word "zoom" in the summary. Similar bug has been reported against composition, though (Bug 177510 - no text zoom in composer).

Thomas please find the dupe.