If this is the image you want to use for your avatar, I just uploaded it with no problem. Part of the ning system gives you the opportunity to trim your graphic appropriately. In this case with the graphic being rectangular, that is a nice feature...just push the graphic until your name is included. I would have uploaded it for you but I can't access your page so you will have to do it yourself. Holler if I can be of any help.
Just uploaded a new avatar and had absolutely no problem at all. In fact once I picked my image and hit SAVE, it was almost instantaneous. The only time I've ever had ning just fail to respond with no error message popping up was when I tried to load a background that was too big. Make sure that your avatar is no larger than 200 x 200 pixels and try again. If you are using a PC, all Windows versions come with Paint. Paint has a nice resizing feature for just this kind of problem.