Question on MP3 file structure

I have a batch of SWF files (Flash files) which contain MP3 data, and I've extracted the MP3 data from the files. It appears I'm not extracting the MP3 files correctly, because the files do not play in most applications, and when I use an MP3 validator, it reports several errors. Interestingly, the files play correctly in QuickTime 7 for Windows, but any other application I try to play them in generates an error. I'm looking for someone who knows MP3 file structure, to tell me where I'm going wrong in extracting the MP3 data from these SWF files. I've attached an example of one of the SWF files, plus the resulting MP3 file that I extracted from it. Currently my method is to search in the SWF file for an MP3 header that starts with hex FFFB, and remove everything before that header. Thanks for your help! The criteria for success is: give instructions for extracting MP3 data from these SWF files, in such a manner that the MP3 files play correctly and validate correctly.