You own ES-10s, right?
Look at the center area protecting the drivers and you can see that convex? protrusion which protects the drivers?
After taking it off many times, it doesn't seem to be as much of a problem currently, though it hurts like hell if it isn't adjusted right. Maybe it is just an outlier, but my ears got caught in that center thing several times (or maybe it is aggravated by having my ES-10s on for a while?)
If I can just circumvent this problem with careful adjustment when putting on, it'd be nice, but the pressure against my ears when making this consideration is somewhat painful.
Ah well, I'll just hope it loosens up eventually and I can adjust.