I've been working though Davies' Tesuji book, and I don't think the solution to snapback problem 2 on page 31 works (or at least, it ends in a ko).
Here's the problem (white to play and capture the big clump of balck stones):
$$W
$$ -------
$$ ......|
$$ ..OOO.|
$$ .OXOX.|
$$ .OXXXa|
$$ .OX.O.|
$$ .OXO..|
$$ ..OXOX|
$$ ...XX.|
$$ ......|
$$ ..,...|
- Click Here To Show Diagram Code
[go]$$W
$$ -------
$$ ......|
$$ ..OOO.|
$$ .OXOX.|
$$ .OXXXa|
$$ .OX.O.|
$$ .OXO..|
$$ ..OXOX|
$$ ...XX.|
$$ ......|
$$ ..,...|[/go]
The given answer is a.
But I'm worried about black responding with 2:
$$W
$$ -------
$$ ......|
$$ ..OOO.|
$$ .OXOX4|
$$ .OXXX1|
$$ .OX.O2|
$$ .OXO.3|
$$ ..OXOX|
$$ ...XX.|
$$ ......|
$$ ..,...|
- Click Here To Show Diagram Code
[go]$$W
$$ -------
$$ ......|
$$ ..OOO.|
$$ .OXOX4|
$$ .OXXX1|
$$ .OX.O2|
$$ .OXO.3|
$$ ..OXOX|
$$ ...XX.|
$$ ......|
$$ ..,...|[/go]
And it seems that now we're left with a ko. Have I missed something?
Cheers
(Oh, and this is my first post, so feel free to let me know if I'm using diagrams wrongly or something

)