@ Neil Banfield,
This is because Cleartype rendering requires knowledge of what is under the text and this cannot be fully known with semi transparency.
All right, I see there's same issue with regular Vista theme engine, i.e
cleartype is disabled on transparent areas.
Curiously, even when I disable transparency,
Vista disable cleartype on area "supposed to be" transparent. Dumb.
However, I've tested Windowsblinds with 100% opaque theme,
and still there's a problem :
* cleartype doesn't work on start menu
* cleartype doesn't work on "breadcrumb navigation".
Also I tried to remove transparency using "Explorer backgrounds" tab of
windowsblinds, and cleartype is not back in the explorer (and that's part where
cleartype is the most usefull , I think).
Finally, I used an opaque theme, and then used a program like "blend" from "Lord Devrexter"
to induce transparency (here : http://devrexster.googlepages.com/, sorry I don't like windows fx ).
Cleartype stayed even on transparent area, so technically it should be possible.
Altho im on a posting hiatus, sorta, I have to second this, most areas I see in vista text do not appear to be antialiased, I use Calibri almost exclusively, and frankly, it looks awful, start menu, taskbar, explorer windows, context menus, etc..
yes, I've been using your rapture theme, and calibri really looked bad, especially in explorer.
I've checked option "I do not want to use any system wide fonts defined by this skin"
and it looks overall better, but still far from perfect in explorer.
I wouldn't say there's no anti-aliasing, but calibri look messed up with the default small
size in explorer. Are you sure Standard Font Smoothing or Cleartype is enabled on your system ?