I am using version 1.77 of SciLexer.dll, but this bug goes back to at least 1.65 (there was a comment in the release list of 1.65 saying that this issue had been fixed, I think).
My main app window is on the primary monitor, and I bring up a second window on a secondary monitor with a Scintilla-enabled control inside it. Autocomplete lists only display on the primary monitor (on the left-hand-edge of the primary monitor, in fact: my secondary monitor is to the left of my primary monitor).
Moving my main app window to the secondary monitor makes no difference: the autocomplete list still appears in the primary monitor only.
Thanks for your help - this is a great bit of software!
(My email is mark_sinclair_mcgarvie@hotmail.com.)
Sorry! I refreshed the page and the bug got re-submitted by mistake.