This is only a minor issue, but when I try to create a block, it takes a couple of seconds for the name of the block to actually change to what I'm typing. Whenever I try to create the block, I have to wait periodically for the block's picture to update.

IE9 x64, Windows 7 x64.

EDIT: …And it just went away. Weird.

maybe something else was causing the entire computer to lag. i have an idea that maybe you didn't press the stop sign before you started editing, i know that causes lag in 1.4.

Yep, that seems to be the problem. Should I report this to be closed?

I'll close it for you.