I broached this subject in another post on iCloud b/c I thought maybe that was the culprit. I was able to get things working that time by updating passwords...although NOT because any passwords were wrong.
Here's the post from that discussion (which got no response)
Now I have the same $@%( problem. I worked on a doc on my iPad earlier today. Go to Pages on my Mac mini and see the doc in the iCloud window, click on it and nothing. In fact, nothing opens on Pages. I tried downloading from iWork through the web and downloading a Pages '09 version to my local drive, but that wouldn't work. Really frustrating and not just a simple case of being out of sync. Versions of Pages on the iPad and Mac are up-to-date.
Mac SE, P-book 160,MacMini,G3,G5,MBP, iPad, lots of boxes with lights and things, Mac OS X (10.5.8), ipad, desk, chair, lamp.....