Out of nowhere, a perfectly compiling Flash app suddenly produces the error: “The name of this class conflicts with the name of another class that was loaded”. No other classes are there to conflict. Everyting is properly set up.
OK. After spending 60 minutes running through code, checking and compiling old versions of my Flash app and googling for solutions, my problem is solved.
Situation:
The file is saved on a shared drive on my Mac.
I run VM-ware.
I compile on my PC (since that is where I have a licenced version of Flahs running.)
The date/time settings of my Virtual Windows PC are not updated properly.
Cause of my problem:
The date/time of the ActionScript FILE on my drive is more “recent” than the date/time my PC CLOCK think it is.
When compiling, Flash compares the date/time of the file with the date/time of the buffered class in “memory”. When the timestamp of the file on disk is placed in the “future” (because my system clock runs behind) a conflict occurs.
My problem is solved by setting the date/time of my PC to the proper value. Hope this helps others.
More info:
Article about the problem
My clue to the solution
Peter Kaptein 
Bruno Rocha
August 18, 2009
Great, tks 😀
Ehsan
November 28, 2012
I do not know how to thank you,
Thank you very much.