I think this might be the old issue of the findbar not opening fast enough. Which can't be helped.
Does it still happen when you type really slowly, like one character per second?

Yes, typing slow doesn't solve anything, upon typing the first char the find dialog comes up empty and only fills from the seconds char on.

Then I think it's a variant of bug #268. I have to press twice the hotkey for the findbar to get focus. In your case, with "Search for text when I start typing" enabled this just means typing. And only the second character will give focus to the findbar.

All issues should be fixed in beta version 2.1.11b1. Please give it a try and let me know if you still have any problems.

Also, I'm sorry it took me so long to get to this.