need help unrooting

first off i was running kangernades 2.2 from rom manager when i switched back to cyanogen 5.0.8 when my power button decided to stop working

so now i want to take it back to the verizon store for a new phone or to be fixed

so i need to go back to stock i flashed my original backup i made just after rooting before going on to custom roms it was way back to 2.0 stock ( rooted )
wich is where i am now kinda

i have the superuser app

but if i run DM updater it says i am not rooted

if i try to flash something ( recovery, Rom, Stock Rom unrooted )
from Rom manager i get an error.....

" an error occurred while attempting to run privileged commands".

i tried downloading a unrooted udate.zip file it said there was an error number 7 or something to that effect if anyone knows of a stock unrooted udate.zip file i can download i will give that a shot.

i figured this as a last resort
http://www.droidforums.net/forum/hacking-help/37717-unroot-unbrick-using-sbf-post-ikithme.html

any other suggestions.

 

i would appreciate it i will give it a shot

 

still have superuser app

just really confused installed a stock 2.1 update.zip file + factory reset + clear cache and still have superuser app

 

push using sbf

so it tells me to hold up on the D-pad while booting for how long what should happen because nothing happens when i do this it just sits with a blank black screen soon as i let go it boots normally

 

thats a negative i am holding up the real up
and the screen does flickr and then it boots normally
right after the flickr no matter hhow many times i let that flickr cycle it still just boots normally after that