Erm, there are many companies out there with budgeds of several millions of dollars, who did not manage to fix "their" software for full vista compatibility yet.. Try a google search for vista-related software problems, and you know what I am talking about.
The dev of mIRC do not have such funds at his disposal... (Correct me if I'm wrong
)
There will be a fix up next, without doubt. It's up to you to show the patience needed (which thousands of other users out there show), or not. But to call someone "lazy" misses the situation by a mile.
Regards
