Imported model.
If the model's first frame is not same as model's default pose deleting all frames messes up the model:
http://dl.dropbox.com/u/4979264/temp/kollar.mdlsteps to reproduce:
object->manage frames
double click a random frame(2nd frame)
double click first frame
select all frames
delete all
Also note that model remains in it's initial pose if you double click the first frame BEFORE double-clicking any other frame. If you double click another frame first then double click the first frame, model is flipped and not in it's initial pose.