I'm having similar problems with my antennae. The Futaba R6208SB receiver has antennae that are fairly short - wit the receiver stuffed as far back into the pod as I can get it, the stripped ends barely make it past the DBox carbon when inserted into the wing tubes. It showed some issues when range checking it while sitting on the ground facing me nose-on (double worst case scenario). It didn't show any issues during moderate range flight tests, but it still makes me nervous.
I think I will order a couple Hirose u.fl cable assemblies
from Digikey - a quick cut and some careful stripping will yield two nice long antennae from each assembly. Should help me sleep better.
I'm not going to seriously fly these models until I get that antenna length thing sorted out.