Since I can't reproduce the issue myself, I'd like to kindly ask you 
for your help:

When the problem occurs, please open Activity Monitor.app (in / 
Applications/Utilities), select iTunes in the list and then select 
"Analyze" from either the menu (all OS versions) or the toolbar (under 
Leopard) and copy and paste the log to the forum or an email to info [- 
a-] iospirit [-point-] com. Please also do the same for Remote Buddy, 
so that the picture is complete.

Thanks in advance!

Best regards, 
Felix Schwarz