Uhm, you want us to tell you what code you have copied from us? Wouldn't it be more efficent and safe to ask the xMule devs? It's not like we are doing code-reviews of your every single commit, so I can't see how we should know what you've copied except in a few cases where it was noticed (by chance I'd wager).
Anway, section 2a is quite interesting, and we at aMule should probably do our best to insure compliance with the GPL as well. 2a states: "You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change.", however, it is not clear to if they want us to add a notice for each and every change (I bloody well hope not, that would be insane), or a notice for any one change.