Incidentally the error message was "You are using Windows" - no not really - it was "can not find this URL" - something like that . . . You probably wondering why I was using Windows? I was using Burncdcc - but I can do this in Puppy now, so . . . Hooray!
I think I will go and rant elsewhere . . .
However the other bug in Mozilla which I have noticed (and others do not seem to have) is still there but it is reduced.
This is what happens in Mozilla 1.0.5 alpha r2. If you click and drag (to resize) Mozilla from the bottom right handle, taking care to click right in the corner - no problem. If you do the same thing but in a bit (to duplicate this effect move out from the center down to the corner - when the icon changes, click and drag. If no jumping upwards occurs (the bug) try again moving in a bit further. If you find the wrong spot (which is the right spot to see the error) the top of mozilla will move up (expand) without you having done anything but click.
I seem to be the only one experiencing this - and I have only just noticed it in 1.0.5 alpha r2 (as it is more subtle). In 1.0.4 I did not bother even trying to click and drag from the bottom right resize handle unless by accident . . .
