This is kind of an odd question, but I've been noticing some unusual barding failures as well and it's set me to wondering:
Do you notice the failures occuring most often right after you log in on the character, or do they happen the entire time you play, especially after the first 20 minutes or so of playing the character? Also, if you've used a power scroll for healing on the character, how much of a gap is there between the character's real healing skill, adjusted healing skill (i.e., with jewelry and other modded items), and the skill cap based on using (or not using) a power scroll? And I guess to complete the set of weird questions, if you're having issues with healing, how much of your healing skill is based on wearing modded items versus "real" healing skill?
People could just be having some wacky run-ins with the RNG, but I do wonder if the developers might not be doing some quiet tinkering with skills to address some issues with GGS or RoT gains and/or evaluating how much value to give to skill that is based on wearing modded items. Am totally guessing at what's going on though....may be absolutely nothing.