Hi, new to the board...

My question is, I am trying to decide if I should disable cashed account passwords on my network. I've used CasheDump to pull the Local LM hashes from several machines and used Rainbow Crack to try and break these hashes to no avail (when i use LM taken from our AD using L0phtcrack it cracks the same passwords fine) ... but Ive also read that the local cashed passwords are salted a different way than regular LM hashes that are stored on the directory.
So what I am asking is, should i really be concerned with the local cashed passwords? I fell like I'm being a bit paranoid when I want to disable the cashe and also my network mgr looks at me like I'm going to cause a bigger problem if our AD goes down and he cant log into a certain machine... Just looking for some outside input..

Thanks,
7R0Y