First things first I've set up all my mods (using ModLoader) with the latest forge. When I hit the test button to launch the game I get a crash, so I disable everything but forge and try again getting this error message. (same message as the first)
I read the report and figure "ok I'll just manually download the deobfuscation data, and put it where it belongs." I attempt to visit the address in the log http://files.minecraftforge.net/fmllibs/deobfuscation_data_missing.zip, but get a "Not Found" error. Now I decide to lurk about the forums for an answer and discover that the files that go into the lib folder can be downloaded from http://files.minecraftforge.net/fmllibs/. I visit the address and download deobfuscation_data_1.5.1.zip. I put it in the lib folder, get the same error and realize that the names don't match so I rename it deobfuscation_data_missing.zip to match the error. Now I get an Invalid Checksum error as detailed below.
So now I have no idea what to do, and beseech the forums for help.
(Note: I have one earlier post where I stupidly tried to piggyback and obviously dying thread, sorry about that.)