Anyone else have this problem?

[rctp10]

If I root and load this ROM into a fresh, out of the box bionic is it necessary to backup first?

The first thing you want to do after rooting and getting cwm is to do a backup, if you've already done your first backup when everything was fresh there is no need to do a backup again unless you found a rom you woulldnt mind using again.

[Nyteravyn]

If I root and load this ROM into a fresh, out of the box bionic is it necessary to backup first?

IMHO... YES... think of it as your personal vzx? file... if anything were to fail.. .(and it sometimes does ) with that origional out of the box backup... *saved to as many places as you can think of, lol* you can flash back to factory fresh.. then the anxiety level will be at a minimum with any new tricks and hacks you might like to try...
and yes, there is the one step unbrick so greatly set up in other posts that has saved many a device... but for on the fly fix's , it is awsome to have your phone able to flash back to factory on the fly... HOPE THAT HELPS...