I've had a look in the sourcecode and couldn't find anything that 
could cause this for available libraries. A library should only be 
greyed out if it had previously been online and then went offline.

Are the respective shared libraries grayed out at the same moment as 
when they are "mounted" in iTunes?

Could you send me a screenshot to the info-address (as found in the 
imprint)?

Does the shared library turn up in Bonjour Browser (=> http://www.tildesoft.com/Programs.html 
, please also send a screenshot of the expanded entry of your shared 
library, if it is displayed there)?

Thanks in advance.

Best regards, 
Felix Schwarz