This solved the problem, and nspluginwrapper configured correctly.
It seems that when nspluginwrapper is looking through the plugins to install it crashes with some plugins (replicatable with "sudo nspluginwrapper -a -v -u").
There are probably other plugins causing this problem, since there are alot of reports of errors.
I'll try to file a bug report under the gcu-plugin package.
After reading bug# 357965 (https:/ /bugs.launchpad .net/ubuntu/ +source/ nspluginwrapper /+bug/357965/ comments/ 5 ), I uninstalled the gcu-plugin (gnome chemistry viewer) with "sudo aptitude purge gcu-plugin"
This solved the problem, and nspluginwrapper configured correctly.
It seems that when nspluginwrapper is looking through the plugins to install it crashes with some plugins (replicatable with "sudo nspluginwrapper -a -v -u").
There are probably other plugins causing this problem, since there are alot of reports of errors.
I'll try to file a bug report under the gcu-plugin package.