Almost everything.

Certain accelerator keys, such as Fn-Left/Right/Up/Down for Brightness/Contrast, and similar, don't work.

I had to change this from perfectly to minor problems, since I have discovered that when I plug the battery in, the mouse pointer soon sort of starts living a life of its own. Clicking on everything in sight, moving scrollbars at random, and so on.

It works, but it lacks RAM.

Specs are:
14.1" LCD
Mobile Intel Celeron 1.33GHz
256MB SDRAM
20GB Ultra ATA/100 HDD
DVD+CD-RW