I did not check previous version, I assumed the behavior never changed.
The behavior isn't really a problem, I reported it for consistency's sake, but it's been a long time since I wanted to say this.
I must say I find the concern about backward compatibilities a bit ridiculous sometimes, I'd rather see consistency and known bugs fixed, always, as far as possible.
Of course some known bugs are not fixed for good reasons, but I think the 'backward compatibilities' reason isn't helping to make mIRC a better program, dropping the support for codepage was a very good thing.
It's not as though the few affected scripts couldn't be fixed either, there's a very good support on this forum and on irc when it comes to help people with their scripts. I think that if you, the author of the program, see a behavior as a bug because that's not how you intented it to work, it should be fixed, again, as far as possible.
Also, we are talking about bugs, meaning the few affected scripts would be using bugs on purpose? It doesn't make sense. It's not that often that the bugs reported here are very subtle, they are usually quite obvious and technically, a script shouldn't use an obvious buggy behavior on purpose, you should blame those scripts instead of blaming mIRC.
Saying a change would affect existing scripts is an assumption, but in the meantime if a bug is reported, it means users are really concerned, I really wonder what are you thought on this.