That's curious. I've found the Ultra Gatorskin to be one of the easier tires to mount, at least on my rims.

I always give the tube and the inside of the tire a thorough coating of talc. I'll sometimes have to wear leather work gloves to pinch those last few inches of bead on to the rim if the tire is being stubborn.

I haven't tried the soapy water trick. I wonder if rubbing alcohol wouldn't work better, since it's fairly slippery and evaporates cleanly.