Sadly, I tried that as well. The 64x pack won't even work for me. I loaded it all up and it just maintained the standard defualt MC textures so I gave up on it and just used the boring 16x defualts.I had a similar problem and have used 128x and 256x packs before as well. I think its the sheer magnitude of objects being re-textured and there is alot going on in the city. However, I had the same stickiness even out in the open. I "solved" my issue by downgrading to the 64x pack.