No, I have not used kext-helper, I used these command;
sudo chown -R 0:0 /System/Library/Extexsions/*
sudo chmod -R 755/System/Library/Extexsions/*

Actually there were two error boxes that popped it after the install (sorry no screen prints), one was complaining about the rtl8187l.kext not loaded properly loaded and the other was a security/permissions error on what I remember to be the /LibraryStartupItems directory.

I re-installed without the RTL8187L driver an all is fine(no errors), I decided to use my D-Link DWL-G122 USB stick for my LAN but would rather have been using the WiFi on the MB.....will continue to investigate !!

btw, the problem seem to be the driver client software that is loaded of the kext it self.