He doesn't re-appear after the first encounter with him. Everytime I pass a "scripted" area, I will hear him asking me if I brought anything for him, but he never ever comes out. Any solutions for this?

It happens often. He may not appear when he speaks, but he'll appear when you'll get to the square you met him (usually a corner).

Is it also completely random as to whether he turns up or not?

Did not realize it was random, but he has both appeared and not shown himself at times.

I'm not sure if this, is your problem, but I did run into bug 1:
Wahooka bugs.
1. Where Wahooka first appears, and asks for something of value,
you (sometimes) can't get him to re-appear. I'm not sure if
this was properly fixed in v1.2, but I have heard that if he
talks to you but doesn't appear, pressing 'Y' will help.
2. Going down to the lower level, then back up to where you are supposed
to meet him for the second time, the game sometimes "hangs, crashes,
aborts, or other weird things". This is also supposed to be fixed
in v1.2.
3. Wahooka doesn't appear in the sewers. If you never walk on the
square necessary to make him appear (??? can it be done???) he will
never show. Sometimes if you have been 'bugged' in an upper level,
he won't appear either. This is a minor annoyance, since all he
does is give you a key to a chest with some good stuff in it. The
chest contains nothing needed to finish the game.
(directly copied from JMeloy's FAQ over at gamefaqs)

hello folks,
as i recall, at this point he can see your inventory contents, if you dont have the item of value he only speaks to you.. when you do have it, he comes to ask for it, you can try a few things to offer, but after a while he will get fed up and go again... and i recall value is measured differently in stonekeep world....
cheers
fivepints

I'm having this problem, too. wahooka refuses to appear in the second level of the keep, at either of the two points where he should appear. his voice comes out, but he doesn't. and i have numerous gems to give him. also, once i got to the sewers he *DID* appear asking for the 3 skulls and reappeared correctly when i returned to give them to him.


also.... i'm having trouble finding a hidden item.... there should be a metarune that doubles rune power hidden on the second level of the keep, but i can't seem to find it where it should be. even went as far as to look for the x/y coordinates in gamecheats.... it's not there. anyone else getting this?
oh yeah.... i'm running windows7 64bit.

just playing this game for the nostalgia factor.... first pc rpg i ever played as a kid.

I don't recall interaction with Wahooka being particularly important anyways. I just ignored
him after awhile, until he joined my party in the Palace of Shadows, I think.

BTW, the double power metarune is hidden in a secret panel at 14.25, not just laying
in the square....