Theirs been plenty of other people experiencing these issues as well. So I would guess that this is a question of the OS version build that is installed.
As M$ brought out a version every 3 or 4 months, theirs about 15 different XP builds, so figuing out what the cause is will be harder than actually having the developers wind the clock back on the development.
Clearly something is wrong with the version 3 branch of this browser, whilst the majority have no issue, some of us are.