I'm using cm_encore_full-18 on my NC. There have been a number of nightly updates. I'm unclear on how updates work. I can go though the whole process again, of course, and overwrite everything. However, I see references from time to time to updating the ROM. Does that require an update.zip? Can I just load the new zip (currently cm_encore_full-25.zip) and install it, without choosing the option to wipe any of the memory sections?
I can only tell you what I do.
I use rom manager.
I download the nightly (25 is the last one as of this writing) to the sd chip in my cell that has a "disk drive" function.
I move the sd chip to my NC.
I power the NC back up
rom manager>install rom from sd card.
that takes you to a list that shows everything at the directory level along with any downloaded files you have on the SD chip.
I just scroll down to cm_encore_full-25.zip and press it.
A window comes up that asks if I want to do back up existing ROM (I don't) and/or wipe data and Cache (again, I don't.)
I only can presume that you have ClockWorkMod installed at this point as well.
That's how I do it.