I 've found that if I try to numerically set a node in an IPO curve (pressing N with the node selected) , eg X=20 Y=0.2 for HaloSize, the node is not located where I meant and the value in the transformation window is reset to 1. Using the mouse to locate the node works OK.
It seems tha Nkey in the IPO window has some problems : it is impossible to enter 0 for a vertex key like before, for example, but it can be cone with the mouse too.