Been making some trial scans with NPE since I downloaded and installed NIS 2011.
The first time, NPE ran perfectly.
The second time, NPE hung on the 'Checking For New Version' screen. I let it go for 30+ minutes before going into Task Manager and terminating NPE.
I deleted NPE from my system, then re-downloaded it the next day.
Same thing. First time, NPE runs fine. Second time, hangs on 'Checking For New Version'.
LiveUpdate on NIS 2011 runs just fine.
Running Windows 7 Home Premium 64-bit with 6GB RAM on a 20/1.5 cable broadband connection.