I don't know if there were any problems before, but the first time I remember hearing about any problems with 311 was from this vulture interview:
Whatís the worst-case scenario?
Not that itís ever happened, but my fear would be that someone would be like, You love those guys, right?Ē Iím sure theyíre nice people ó [their music] isnít my cup of tea.
And it's just an off hand comment, I don't know if it was direct shots being fired.
In high school and college years I really liked 311, although I haven't found myself going back and listening to their stuff as much as some other bands, and certainly don't listen to them as much as Beasties, but I was a bit shocked when Mike D said that.
I agree with Sir SkratchaLot's theory though.