il look into the shield bug a bit more. ive seen the part of the code that checks shield armor and implemented optional difficulty scaling there. armor is applied 4 times in shiphit.cpp, once for shields, once for hull in ship_do_damage(), and twice in do_subobj_hit_stuff() for subsystems (im not sure why, one call is before any difficulty scaling is done, so the scale factor is set to 1.0f for that call, i did that so as not to break existing behavior). it seems nothing different is done for player shields here. it would get scaled by the difficulty factor when it goes through armor computation. you could try running it on insane to make sure this factor is 1, also make sure shields aren't being pierced by your weapon. you can also use the feature that fixes 2493 and set where the scaling is done.
say you had an input of 10 damage, running on easy mode that would be 2 damage, and if your shield armor reduced damage by another 2, it could result in 0 shield damage. im wondering if it isnt the same bug manifested in a different way. you could try setting +Difficulty Scale Type: last, as well and see if the shield armor is still not working. and Spoon, if you felt like i was taking Droid803 word over yours, its because he presented me with more data, and if i came off as rude in my previous post it was because i was really really tired

regardless this thread is about fixing 2493, not 2494, though i am interested in squashing that bug as well. but first im primarily concerned with this:
is 2493 fixed?
is there any change to retail behavior?
and secondarily:
do my new features work as advertised?
*edit*
found a bug where if no armor type was applied (for example retail) difficulty scaling would not be factored in (will be fixed in next build).