I'm guessing she dissed him when she reneged on her decision not to record a song with her and Justin Timberlake that Timbaland was supposed to produce. Timberlake and Timbaland were trying to help her get her career back, but knowing how ignorant Britney can be, she probably said something that basically said she's too good for them and she wants nothing to do with them and that she can bring her own career back. Unfortunately, I don't think this is the case.