i was reading the DIVX forum a while back, in regards to fakes someone recommended a program called virtualdub, to check out a file you alread have but wont play, open the file in virtualdub, then go file, and propertys, if it says its uncompressed rgb, its a fake. solved a few mysterys for me, so it wasent a codec prob after all
virtualdub is freeware and you can get it
here