There has been a lot of discussion recently on BROL and the RANS Yahoo discussion group about some instances of riser pieces failing from stress, typically generated from pulling/pushing on the "chopper" style handlebars. It seems to fail below the weld, shown by the thin, shiny line at the TOP of the weld in this photo.
RANS is offering to replace any welded risers with one-piece forged ones. Mine failed a year ago, but not like this -- my threads stripped out from me pushing up on the handlebars a lot more than I should have.
If you have a Stratus XP with the chopper bars, take advantage of their offer... I'm sending the risers back from both our bikes.