is divided into two lines because of that and the stuff will be interpreted as:
stats='toolbar=no,location=no,directories=no,statu [without the terminating quote (')] and a second line:
s='no,menubar=no,height=400,width=350,' (which would be something like the definition of a variable called "s" -> s='something'
Without eliminating this linebreak, the script did not run at all (even with only your six example keywords).
Anyway it seems, that this is not the cause for your problem as you said, that the script runs on your machine with up to 250 keywords...
Cheers - Pit