So, yeah.

Some, obviously, you get them on the first try straight off.

But how come is it you always seem to get crap die rolls, on ones that you need good rolls to get?

Die rolls:
good (before invoking some Lore from a scroll)
lame
miserable
lame
pathetic
poor
poor
(Here is where my scroll ran out of charges, so I had to go fetch the Mage to cast on him.)
poor
lame
adequate
horribly wrong (box explodes, killing me & wounding the Mage)

<mutter, curse, grumble, swear, kick puppy>

>But how come is it you always seem to get crap die rolls, on ones that you need good rolls to get?

>It is well known that using trap lore not only reduces your experience while increasing your disarm RT, but also activates a modifier that gives an unseen -50 to your die roll.

This is a hidden penalty for amateurism. Its actually triggered by using lore on the subsequent attempt but not the first disarm. You won't get hit by it as long as you make the decision to use lore from detect rolls rather than disarm rolls. You probably stacked it too, by switching to othercast from selfcast. Remember what the footpad tells you about fumbling around before blowing yourself up!