ReferenceError: Error #1065 : "Variable xxx is not defined"

Hi! I’ve just switched from cs3 to cs4, and I’m having a quite annoing problem:

Suppose a simple blank new flash document.
Suppose a simple mc symbol in the library, say ‘square’, with some actionscript, say a simple stop() command. No linkage/export class name.

THE PROBLEM: as I put an instance of it on the stage, while testing I get this error:
ReferenceError: Error #1065: Variable square_1 is not defined.
It attaches the _1 to the symbol name and gives me that error.

  • I’ve observed this: if I cut out the stop() command (or any actionscript, I suppose), I don’t get any error while testing.

  • I’ve also observed this: If I put a class identifier for the square symbol, the problem disappears. Obviously, I definitely don’t want to put a class identifier for every symbol I use with some little AS command inside…

Any idea? This appears for all the symbols with AS code inside.

Since my Flash CS4 is an upgrade I have both flash CS3 (the original licence) and flash CS4 installed on my Mac (iMac intel core 2 duo, 2.4 Gh, 10.5.5). Could it be some cs3/cs4 conflict?

If you want, I can attach the fla.