Many bugs resolved following these steps:

[DnaCowboy]

First of all I'd like to thank INKBLOT who found this fix, thanks very much.

 

1: NEVER load a save directly from the menu that pops up when you hit ESC. or following death, instead load only from the main menu (if you hit ESC, choose 'Quit', then load from the main menu).

2:  When you save and quit the game, shut down the Steam client as well. 

 

Once I did that all my problems went away:

1: Grappling hook option in Dragon Egg and Chasm in Caves FIXED

2: Quests disappearing. FIXED

3: Items disappearing FIXED

4:  Fighter not attacking: FIXED

5: menu titles and sub menu titles disappearing: FIXED

Edited August 30, 2014 by DnaCowboy

[Karkarov]

Interesting, will give it a try on my next new character.

[Messier-31]

Too bad that this doesn't solve the "new game crash"

[Marceror]

I think you just got lucky. I've had items disappear without ever saving my game, at all. Sometimes all it takes is walking from Dyrford into the inn for items to vanish.

[DnaCowboy]

I think you just got lucky. I've had items disappear without ever saving my game, at all. Sometimes all it takes is walking from Dyrford into the inn for items to vanish.

 

Its repeatable, I've carried out the method required to cause items to disappear and then followed the 'fix' method and it works every time.

To be fair to you though I have never had a problem whereby walking to the Inn caused items to vanish!

[Marceror]

Has happened to me at least twice. Perhaps bad luck on my part.