Indeed ... resetting these preferences had no effect ... as you predicted!

I tried a project without any VST ... blank project ... created a dummy MIDI track ... press nudge ...=crash again, 

This happens in both of my X86 AND X64 installation of X2a. 

Problem does NOT occur on my X1 installation. 

I checked my Maudio audiophile 2496 drivers: they were up-to-date@ 6.0.8. 

that's very odd.. because pretty much else of the software is working fine...

I've submitted a few bug reports to cakewalk .. but I've never been "lucky" enough to have any kind of follow-up. 
So I'll try to reach tech support directly then .. 

I guess it's system-related, as my other computer having the same X2 is Nudging just fine, 
but still, I find odd that both 32 and 64 bit versions are crashing at the very same function, 
there must be a single DLL or something that got corrupted, that I could simply replace. 
(that I would need to know which file, as I rather not re-install everything ... )

If ever you have other ideas for me to try ... please send them my way ! :) 

Thanks again for your help ! 

Cheers ! 
V