Minecraft 1.5.2 stuck on "Done loading" screen after installing Forge on Mac

[tw_mix]

I am trying to install mods on Minecraft 1.5.2 on Mac OS X 10.7.5.  Vanilla Minecraft is working flawlessly, but when I install Forge, trying both 7.8.1.737 and 7.8.1.738, I cannot launch Minecraft.  It gets stuck on the hated "Updating Minecraft - Done loading" screen.  I'm pretty sure I installed Forge correctly, since I've done it on Windows so many times before; I deleted the META-INF folder before copying the files over and all that jazz.  I would post a log, but the freeze happens before Minecraft gets a chance to generate either a Forge log or a client log.  Also, in case it's relevant, I've tried this with both Java 6 and Java 7.  What am I doing wrong?

 

[luacs1998]

Use multimc. Macs are hopeless for manual modding.