ive got an error that i need to fix.......!!!!!!

ive had my site running for a year so far with the mod running fine and dandy until the other day i noticed that i had bots coming to my sites spamming me and trying to access my admin section.

I followed the instructions on how to change the admin section name to something else.... after changing the admin section i enter the url and i get forwarded to a page not found site map page! any ideas???