sonar LE and lame mp3 encoder

i had a minor disaster with the computer and had to do a system restore. i have had to reinstall sonar LE which was not an issue but it doesnt recognise lame anymore. i tried following the guides on here and elsewhere and whenever i finish filling in the encoder config box and click save it just erases the name in the friendly name box and thats it. it doesnt add it to the encoder options and i cant find any way to stop it from happening. all the rest of the info on the config box stays, it just deletes that friendly name and does nothing. 
i have a vague recollection about this same thing happening when i first set it up but i cannot figure out how it sorted it. its really quite annoying. i did check and lame is still there and still in the shared utilities folder. help would be much appreciated as that way of working was great for me before.