Got my XD about a month ago and have taken it shooting weekly. For my first outing, I put 500 rounds of Rem UMC through it without issue. Cleaned, lubed, and went back a week later with 250 rounds of WWB and got a handful of FTEs. Suspected my cleaning job (this is my first gun), so I gussied it up with much vigor, and took it back a week later with 300 rounds of WWB --- got a slightly larger handful of FTEs. My shooting partner suggested it might be a bad mag, so we marked 'em, gave the XD the ol' once over, and went back to the range a week later (today) with 200 rounds of WWB --- got even more FTEs, spread across two mags, with one mag having 3 FTEs during the course of fire.
Anyway, we're going back tomorrow with both some UMC and WWB in hand for testing. Details as they develop...