how to resolve it????

Hi,
I've succeded in dumping Powerstrip and rebuilding IT, but now executing it I receive a msg box ( followed by a beep) saying the checksum is altered..... I want to know if there's a way of knowing at wich address the msgbox has been called.... there're no reference string in .exe, I don't know if you've understood my problem, btw powerstirp is protected with asprotect, don't know wich version . Bye and thanks in advice