I just used automatic update on my powerPC to upgrade to OSX 10.5.8. This update also installed Safari 4. I then installed Reader 9.1 (latest version). The reader install was clean, no previous versions on my machine. When I opened Reader for the first time, it did everything it needed to to install the plugin for Safari.
Now, when I browse PDF's, if I have Reader set to display pdfs in the browser and I try to open a pdf through a link with the property target="_blank" (i.e. set to open in a new window or tab), the plugin hangs. If I open a document through a normal link (target="_self"), documents open normally. If I uncheck the Reader preference for displaying documents in the browser (i.e. using the plugin), documents download and display in Reader properly.
Is the plugin currently not working properly in Safari 4, or is there some way to configure it so that links that open pdfs in a new window/tab don't hang?
I came across this problem because multiple users of the website I work on complained about this problem, and I was troubleshooting their reports, so this isn't a one-off problem. They are the ones who provided me with the software versions, that I then duplicated on my dev machine and immediately duplicated the problem. This is going to happen to any powerPC/OSX10.5 users who keep up on their security updates and their Reader updates, and possibly to other Apple platform and OS version combinations as well.