Damn I was wanting to post this in bug reports since the behavior is off in my opinion.
You did post this in 'Bug Reports', it was moved. It's certainly not an mIRC bug.
Thanks for the alias but it doesn't account for all the ways a query window can be opened.
The alias takes account for all the ways you
open a query window.
+ on open
Making the on open work no matter how the window was opened is the best solution.
Might be an issue in terms of backwards compatibility.