The ATA is set at a certain measurement so that there's the right amount of load on the limbs in a "static" position. Anything under that recommeded ATA is going to add more load. Overload can show up as anything from cracked limbs, to shorter limb life, tuning issues, etc. I'd make sure the bow is set to spec.
2006 Rytera Bullet X 60#---2008 Moab 70#
2008/12 Firecat 60#--- 2010 Warthog 70#
2009 Warthog 70#
2010 Strother SR-71 65# & 2012 Strother Rush 65#
2012 Strother SX Rush 60# & 2011 Strother Infinity 70#
BSD strings and cables
Yeah, I know I'm grumpy and opinionated.
Actually according to JoelC and Martin's website, there is a little more flexiblity than that, 1/4" shouldn't matter that much.
Recurves: 40lb X-200, 45 & 50lb Hunters, 45lb Mamba