I am trying to wrote a script and once again, I am in trouble.
I see in another posts than some people found workaround to make script runs, even if it do not make something in the script.
That seems for me that the trouble comes from somewhere else like the compilator itself.
Let me explain, what happened yesterday with my new script. So together, we may found why some script do not work and after work withou obvious reason.
I develop offline (notepad) a script and compile it when finished. I get just few erros like missing ; and so on.
The script does not work, so after I compile it in SL. Lot of errors have been show. A correct them there and back to OG with the modified script.
I get an error message, in line 42 (it will be important),. tell me that use == to compare 2 strings is ambigous.
The compiler expects integer.
The first strange thing here, the compiler does not complain for the same kind of comparaison few lines below.
My first approach, is to change the comparaison by a function that does the same.
The compilation notice me that llGetStringLength is not implemented or some think like that.
Keeping in mind that my first script in OG loop without reason and I was unable to reproduce the problem in another code.
I am guessing that the trrouble does not come from the script itself, even if bugged it must a least do something.
Because the line 42 is design to check the data value, it is not snecessary for the debugging phase.
So I comment the line and recompile the script. And get the same error? 
It become obvious that whatever I do, create a new script object, put it on a new prims. I ever get the same error in line 42.
Except that this line does not exist anymore. So for unknown reason the code compiled is the same, what ever the source is.
If I cannot explain, what exactely happened, I found something that can notice us when troubles happen for outside reason than the script.
Close the scritp windows and reopen it. Normally the script code muts appears. Yesterday, the code never show back