Hi,
i had a problem on my Vista Laptop too. Calibre started, but didnīt show the GUI. Taskmanager showed a steady 50% CPU-Time of the process.
I rememberd yesterday, that on the same day of the release of calibre 0.5 that Microsofts Windowsdefender got an update and found the hosts-file suspicious and I clicked repair.
I found this news yesterday:
http://www.h-online.com/security/Win...--/news/112814
I looked and the localhost-part on my system had been deleted. I edited the file and voila, the GUI is back
Bye
Thomas
Bye
Thomas