IBR only applied to some objects matching leaf node Images

So...I've got this policy in which I have enabled Multiconnect and IBR (and assemble content on proxy) on leaf type Images. Problem is that for some gif I don't get any IBR or Multiconnect, but for most I do.

 

 

So 2 different gif, in same directory, same referrer, 1 gets IBR/Multiconnect, one gets nothing. X-PVInfo shows that WA has classified them the same (same S, A types).

 

 

I attach HTTP Watch screen shots below of both. Any ideas anyone?