Dunno if this will help, but i have the same sail But on an X6 mast, and 2 weeks ago i had a guy who i have no doubt knows what hes talking about, (he can certainly sail better than me), advise me that i had too much outhaul on in my attempt to depower the rig, so we let it out a bit and got a bit more curve in the sail, but then i had the same problem, the only way i could pop the bottom cam was to kick the batton after each gybe.... hmmm
Conclusion..... im going to put a little more outhaul on the way i'm used to doing it next time. my outhaul setting is 2-3 cms longer the recomended. Now i'm not saying this is right but it works for me.
I think both Formulanova and Bertie are heading in the right direction here, i find the V8 has a real narrow sweet spot and for me its a tricky sail to rig right, with my lack of experience. It may be the mast or a little d/haul here, a little o/haul there and finally it will work right.
I also believe that the bend characteristics of NP masts changed at some point, and i guess maybe its possible the X5 bends a little different to the x3/x6, therefore not suiting the sail quite as well as the later vintage masts.
The other thing about the V8 i find is its just a heavy feeling sail compared to my others, and definately not as nice to use as my other 3 un-cammed sails.
Good luck