I'm on my 4th Mavic Kysyrium back wheel, they crack badly in the same way and the nipples pull out. Always around the 2500 mile mark and 160 miles riding time, very consistent. Luckilly I have the MP3 warranty so they keep getting replaced. But it is not fun overall having to keep a constant check on them and having to swap wheels if your doing a very long ride and your close to 2500 miles already ridden. My last wheel, every spoke was pulling out of the rim on the drive side.