Now heres an odd one: its been the same on my laptop versions 6.2 and 6.3 - there is a problem with alpha blending on the start menu on many themes. The shadow is solid and there is no transparency. However, when I mouseover objectdock with the start menu 'up' i see the alphablending kick in - the shadows soften and and the start menu show some level of transparency. I have a dell inspiron 1525 with a relatively crappy intel graphics chipset but it scores 3.1 vista index and can cope with WB. I have the latest drivers etc.
For example, plastic fantastic GUIchamps entry works fine but the WVS suffers this problem. I guess I'll upload images showing the flaw if needed.
Any ideas though?