[All?] The RNG is funny

I'm thinking there's a minor bug in a recent version of Zangband, which
is what I'm playing -- nearly every "excellent" cloak I find these days
has a negative attached to it. Like, I'll find a cloak of Immolation,
[1,-11] or similar. Weird.

Anyway, I found this interesting crossbow just now at dl 62 (remember,
they've stretched out the dungeon some in more recent versions of Z, so
compared to vanilla that's, what, about vanilla dl 45-50 or so? A recent
quest had me kill Khamul the Easterling, who's claimed to reside at dl
74, so that should give you some idea.):

The Light Crossbow 'Atarmith' (x4) (+20,+13) (+2)

Item Attributes:

It affects your ability to tunnel. [!]
It provides resistance to blindness.
It speeds your regenerative powers.
It cannot be harmed by (blah blah blah: the usual)

A crossbow which affects my TUNNELING? What, I use bolts to blast
through the rock, or what?

Nearly completely useless, of course, at this level, for my dwarf
warrior wielding Stormbringer very carefully (I got the good version,
that drains experience, rather than aggravating). Now, if only I could
find some damn speed -- when I first found the "special" crossbow I
thought I was there. Oh well.

(This seems to be Z 2.6.2 or thereabouts, based on the z_update file)

-Josh