If u r using SonyEricsson set then press and hold the "c" key while u connect the cable to ur phone. Remember that the phone must be in a off state and the battery must still be in the phone (DUH)...
XS++ 2.0 works with w810i. I tryed it myself. I also used FAR manager and i updated my phone with "Accoustic driver" and "Camera Driver". Now i have a super loud and high bass sound and a super camera with 16X zoom (A little blurry at 16X) and super night mode (No need to use flash, only wait 2 sec to take a picture)...