The correct rendering: Opera 5.01:

Opera 5.01

The incorrect rendering in Mozilla 0.6 (positioning works floating doesn't because I don't see any reason, why floated blocks should be lower as the parent blocks):

Mozilla 0.6

The incorrect rendering in MS IE 5.5 Windows: floating works but positioning doesn't because position: fixed doesn't work and MS IE counts the position of the background image starting from the borders, not from the viewport. MS IE 5.5 Win