why --slices 4 on the divx plus hd profile (megui)? it's necesary or not?

[OvejaNegra]

as the title says.
is not listed here:
http://developer.divx.com/docs/divx_plus_hd/Creation_with_x264/

so now im afraid of my 52 encodes must be re-done befor burn to disk.

(maybe not)
thanks

EDIT!
Wops! I just updated my megui profiles and now it's gone.