Associating .vbs files with Notepad++ breaks VBScript

I associated .vbs files with Notepad++ 5.1, thinking that will make editing them more convenient and prevent accidentally running some nasty script. Actually, it totally disabled VBScript. When I tried to install a new driver for my network card, I was told "There is no script engine for file extension VBS". Re-registering vbscript.dll and other DLLs didn't help. Running Notepad++ as administrator and removing the file association fixed the problem.