It means exactly what it says: the laser lens could not be 'focused' on the media. This can be for a varety of reasons, including:
Your Superdrive needs a clean: any CD/DVD lens cleaner using tiny brushes will do the job.
You are using poor quality media: most of us here recommend Verbatim, Maxell, Fuji or Taiyo Juden DVD-R, and a burn speed of no more than 4x
Pure voodoo, but heck, it's worth a try!
Just to simplify:
Open System Preferences.
Click on "International"
Under "Languages": Drag any of the other languages to the top,
then drag English back to the top.
Set "Order for sorted lists" to English
Set "Word Break" to English (United States, computer)
Close System Preferences
I was VERY leary of trying this - because . . . so off the beatin path for something to do with a laser issue - But IT WORKED ! I had stopped using my burner for over a year now and used another system to burn what I needed. I had techs at APPLE open it up and tell me my CDRW was just bad and required replacement.
I came across a few threads in MacTalk / MacRumors and such, about blowing compressed air through the area to clean the laser eye, that didn't work. I then ran across this unique thread to change around the language pref and it works fine . . .
thanx so much for sharing the thread Klaus