I get a strange kind of scaling problem for some fonts in Illustrator as well as Photoshop.
For example here is Helvetica Neue Light at 18px. You can see that the letters 'r' and 'v' are the wrong height:
Image may be NSFW.
Clik here to view.
At font sizes above 18px I don't get a problem.
In non-Adobe programs (e.g. Textedit) the font renders OK at all font sizes.
Any ideas?