Sounds like you Loading 6 is the fix for the x1b v-vocal fix on your machine.

Hopefully it will still work after you re-install 6. 

Does the version of Logic you're using have native tools that do this work, or is it a 3rd party plug-in? 

Thanks,
-D

Thought of another obvious thing:

Were you going to submit the crash dump to CW support to find out what is causing the v-vocal crash? 

He said it was crashing when it was drawing the wave form, maybe delete everything in the picture cache folder? I think I read somewhere that doing that fixes some things.

I have found that freezing all the soft synths in a project allows V-Vocal to work.
I get crashes when projects get large in the >4Gb RAM usage area....
If synths are frozen this reduces the RAm used and V-Vocal starts working again.
I believe V-Vocal has issues with higher memory addresses.
I wish Cakewalk would sort it out........or I might have to splash out on melodyne and I really don't want to have to.

FWIW, I had some issues with it not working in X1a. X1b fixed it and I have had no trouble with it what so ever. Although, I use it more to fine tune an instrument note from time to time. I am blessed to work with some pretty great singers so I use it less on them than I do for other aspects. I wish you luck in finding the problem.

Hi Guys... I am new to the forum although a long time Sonar user! I have always had problems with V-Vocal although it took me quite some time to discover that it was V-Vocal that was causing all my misery... To the point where I bought a new system!!! I am using a i7 system now with 32gb RAM and tons of storage!!... and guess what?.. V-Vocal still crashed!!.. After trawling through various threads on the subject I came across a post that solved the problem.. I replaced the AUD.INI file in X2!! Actually I changed the name of the file to MUD.INI and forced Sonar to create a new AUD file when I reopened sonar.. Dont know if this will work for everyone but it sure solved all my V_Vocal crash problems.. Hope this helps!

Just want to add to this that bitflipper wrote a brilliant post on getting the most out of VVocal.  It may have been in the techniques forum.  If I find it I'll post it.
 
I printed it out, it was so good, and it's in my pile of useful info on my desk.

ypu may have multiple copies of the chronos.dll file on your computer. you should do a search for that file name. if you have more than one it could be a problem.

I recently deleted 8 bars of music in my project and of course V-Vocal clips were corrupted after. V-Vocal is in a bad shape.

Why use X1 B? Why not use X1 D?