I have the same problem since month or two. I've tried put new title to the database and when I clicked "Go" there's only "Logging in..." in the bottom bar and PVD is frozen and unresponsive (I haven't an account on IMDB, so I don't have a set it in PVD). Then I must kill the process with the task manager. My PVD version is 0.9.9.21 and OS is Win XP SP3. I didn't install any other programs, I didn't change any settings in the system or PVD. Everything worked well and just stopped one day and still doesn't work. Reinstall PVD does not help
The strange thing is, that I have another computer and everything almost is fine, program works (0.9.9.21, Win XP SP2), but sometimes has the same symptoms like my first computer, but very rarely.