Adjust mouse keys in 12.04?
This is more of a workaround than an answer to your question. You can use xkbset to adjust the speed of the cursor when using the mouse keys feature. The idea came from this post:
http://www.exuro.co.uk/2012/07/114/
The setting I found most comfortable was:
xkbset ma 60 10 10 5 2
Hope that helps!