There is a different behavior with the focus for the editbox in 6.3 and in 6.21, here is the step to reproduce :

-you should have two channel window open
-The focus is on the editbox of the active channel
-Select a nick in the nicklist
-The editbox lost the focus
-Click on another channel
-Comeback in the previous channel

In mIRC 6.21, the editbox of the first channel will has the focus, on mIRC 6.3, it's not the case

The behavior in the mIRC 6.21 was much better

This happened too in 6.21 where I would try to type something and focus is on the nicklist so menu's popup or I end up accidently kicking or ignoring someone or whatever. It didn't happen an awful lot, but since 6.3 it's been pissing me off, it seems a lot worse.

Uh ? If focus is on the nicklist, it's normal that menu's popup when you type something

That part isn't the problem, I know that's supposed to happen, but I expect the editbox to have focus and it doesn't, as you explained in your OP. I guess I mean when a window with an editbox is activated, the editbox should have focus by default.

Hum, it's works fine for me on 6.21, can you reproduce that with the step i given ? or with different manipulation ?

ugh .. I'm confirming your report. On 6.21 it behaved as expected, on 6.3 it does not.

I've noticed this as well. It seems to happen to me when I alt-tab between apps. Sometimes (not always and I don't know the reason), it will have the nick list active instead of the editbox and I'll start typing in that instead of the editbox. This happens a lot in 6.3.

Thanks this has been fixed for the next version.

a work around could be:

on 1:ACTIVE:#: editbox -fa