This is not just a Tiger problem. This happens in OS 10.3 as well, and possibly 10.2. And it's not consistent either, at least between different computers - on many different Macs I've setup with 10.3.8, some have this problem and some not. I haven't seen a pattern yet.

On a related note, I find the AICB clipboard more useful, it's needed if you want to paste paths or shapes into Photoshop, otherwise all you get is as pixels.

And, it may or may not be obvious, but you must make sure the AICB clipboard format is selected. With no clipboard formats selected, it defaults to PDF.

The AICB format with "preserve paths" selected is also useful in conjunction with After Effects. The paths can be used to create masks or even motion paths. This trick can very handy:

1) Draw a path in Illustrator.
2) copy it.
3) Select any position-based parameter of a layer by clicking on the word "position" for the target layer on the After Effects timeline (either of the layer itself or for any filter that uses position coordinates).
4) Select paste, and After Effects will automatically create keyframes to form a motion path that matches the path you drew in Illlustrator. (Various methods may then be used to edit the path or adjust the timing.)

Possible uses include:
- easily create a "write-on" title
- create a spiral motion path, or star-shaped, or whatever shape you want
- create a motion path that outlines some element of a background image

If you haven't used this method before, try it out. Have fun!