Okay I am having the strangest problem. I installed Autobag and Event Alert via Curse Client. I could see both there. I could see both in my addon folder in the path C:/program files/world of warcraft/interface/addons. But when I log into the game, the addons don't show up on my addon list. I have taken the following steps trying to fix the problem:

I tried reinstalling via Curse Client
I tried restarting Curse Client
I tried restarting WoW
I tried manually installing them

I tried deleting them, removing the saved variables from a previous version, and manually installing them again
I tried restarting my computer

What gives? They are there in the folder and I see them. All my other addons work. I have the box checked to load out of date addons. GAH!!!

EDIT: I ran a registry clean up and WoW Repair Utility and restarted my comp again. Event Alert showed up but AutoBag still does not. I have since installed a different addon and it works fine... but Autobag still does not appear in my addons list.

Switch on LUA-Scripterrors ... this will probably help to see where the problem is.

Turns out the problem was with the addon filename and was fixed by the author today. Gah, all that headache over a space, lol