Hi.
This could be related to the problem you were having with your keywords not being separated with commas. You see, the keywords are contained in iPhoto's albumdata.xml file, which is what enables the other applications to read your library. So if there is a glitch with the keywords, or the xml file is malformed, the library won't show up in the Media Pane of the other applications.
First, is your iPhoto library being run from an external hard drive? If so, make sure the name of that drive has no non-ascii characters (anything other than a-z and 0-9). For example, I've seen this happen if the drive is named "Pictures & Movies" where the & caused the whole problem. An external drive should be formatted Mac OS Extended. Post back if yours is not.
If an external hard drive is not the problem, then you need to open iPhoto's Preferences and check your keyword list there. Look for non-ascii characters and remove them. Also be sure that there are no spaces at the beginning or end of the keywords. Spaces between words in a 2-word entry have not caused me this problem.
For more detailed information, read this thread:
http://discussions.apple.com/thread.jspa?messageID=3870956
Dave E gave great instructions on how to read the xml file to identify if one of the keywords is causing the trouble. You can't correct the problem from inside the xml file, but if you identify a bad keyword you can go back to iPhoto's keyword Preferences and correct it. Farther down the thread I posted some screenshots to help illustrate a possible cause.
Post back here if you have any questions.
Regards.