Help required!

I'm running Windows XP-Pro and IE6 on a HP PIII OmniBook.

My usual Internet browsing pattern is to have several windows open, though most minimised. When a page is loading I will minimise it and maximise another to read it.

My problem is that since yesterday the active window keeps changing all by itself. I can be half way through filling in a form, or reading something and another browser window becomes active.

These are not pop up windows, but windows I have opened, for example I'll often browse multiple PPRuNe windows, letting one load whilst I read another.

Can anyone offer a solution so that I control which window is active rather than this infernal machine?

Thanks in advance.

Clarrie