Hey PJ,

I've experienced this before and, while I never fixed the problem, I have a good idea what was causing it for me.  Your skill might be different, but I have an idea where to start looking: the alignment of your nether crystals.

I'm just assuming that the nether crystals are in fact units that explode on death.  Depending on the way they're set up, the alignment might be the problem.  If they're Neutral or Hostile, I don't think they'll display the damage they do to other monsters.  It could also be a problem with the way they deal their damage.

I'll take a look at the files if you want.  Just let me know if I can check the latest version of the TL1CP or if I should wait for you to send me your files.

Did you ever manage to find out what is causing it? I have noticed that a lot of skills do not seem to show damage numbers correctly, this seems to be mainly dots like burn.

The weird part is, i can see the DOT damage from a skill like spell:Frost but not the fire damage from firebash.

Also anything that casts a skill like wand of chaos will not show damage, and you cannot see the damage of charged bolts (From the shock effect).