Does it freeze while loading?
The only things I've copied from the XL version on to this one are stock static meshes and some bsp geometry. Since this map worked fine on both PC and PS3 prior to the update and since the stuff I copied couldn't be the cause of this I've come to the conclusion that maybe it's the grass volume causing this problem. That's really the only thing I've added that is "different" in terms of type of object. Before the update there were no foliage volumes just regular static meshes for the grass.
However since I've already made 2 other maps that have foliage volumes and work on both PS3 and PC (Tiberium, Nowhere), I took a look in the properties and found that the only difference between the foliage volumes on those 2 maps and the foliage volumes on this map and NITP-XL is that the collision is set to custom default... whereas on the other 2 maps it's set to no collision.
Could this be it?