Not really a lounge item as it is Encore Specific - but the answer is to be certain you have installed the library properly.
Try actually clicking on one of the headings in the Library panel, and if it is properly installed it should now begin the initialization process (this only needs to happen once for each section such as "Corporate" "Wedding" "Entertainment" etc.
To see if it is installed, go to
C:/Program Files/Adobe/Encore/Library and see what is in there (location might not be 100% correct as I am away from a CS4 installation right now)
I am having the same issue. I cannot find the Library link from the media menu going through the Adobe program file. What did you do to resolve this?
I am loading CS3 ENCORE and there is no menu library and none on my CD. How did you solve your ENCORE menu library problem?