"1024: Overriding a function that is not marked for override" error given incorrectly

Steps to reproduce:
1. Have a class which extends another class which extends Button
2. Attempt to compile project

Actual Results:
"1024: Overriding a function that is not marked for override" Error give on line 1 of the class. The problem is, it doesn't tell me which member is causing a problem. On top of that, this class contains no functions! Commenting out every single line of code except for the 'public class ButtonNoBg ...' line, still gives the error.

Expected Results:
I expected the error to tell me the correct class causing the problem, and point to the correct line in that class

Notes:
This project compiled fine with Flex 4.1. My guess is a combination of two things are causing this error in Flex 4.5:
1. A new member was added to one of the Flex classes, which now conflicts with one of my class members
2. The compiler is not telling which one is causing the error

Please let me know if there is anything I can do to help solve this problem.