After having communication issues trying to order a smud 30.9mm seatpost for my 29er epic i then ordered a Tune carbon one. I use the old model specialized phenom saddles with Ti rails but when torquing up the bolts to the recommended levels I can move the saddle slightly by twisting it side to side. My new ultimate worked fine on my other bike with this saddle... Anyone else suffered similar issues ?

In reality, saddles and seatposts are not always compatible. The spacings of saddle rails and seatpost clamps are often 1 or 2mm different. And the diameter of saddle rails does not always fit well in seatpost clamps. Plus, both sides of seatpost clamps are not always parallel - the front & rear yokes themselves can be different!

Maybe you can find someone with identical parts to be able to tell if this is a unique issue or whether your two parts just don't fit. Either way, sounds like you have to go to another seatpost. Just sayin.

Have now tried another brand of seat and it does fit better so it maybe its the small tolerances previously mentioned. However the yokes still dont sit entirely flat on the rails due to the seat angle on the Epic 29 frame so i have ordered a different type of yoke similar to the MCFK ones to hopefully address it completely. Another option would be to maybe file a small angle where the yokes sit on the rails but i dont really feel comfortable doing that..

Go with MACK, PoP or AX yokes because they work at any angle and so are more carbon rail friendly.