ID3v2.4 Frame sizes are calculated incorrectly. Currently these sizes are calculated as a plain 32-bit integer rather than as a 32-bit sync-safe integer. This means that the size of any frame larger than 0x7f is being returned incorrectly. In addition, once you hit a frame that's > 0x7f, processing of frames will exit so no further frames will be processed. A good example of this is the MCDI tag that is often big enough to trigger this issue.