Definately avoid lifts for the time being that involve the lower back, but I guess that's obvious.
I too, love the RDL's, and I have traditionally had lower back problems, but they went away eventually due to a priority on back conditioning and strength. Unless your problem is something other than a "simple" lifting injury (I say that knowing full well back injuries can be misleading), once you are healed, remember to stretch until you think it's crazy to stretch any more, then stretch a little more.
Proper technique can be difficult to realize, and your worst enemy on the deadlifts. Make sure the back is straight. Don't look at the mirror or the floor. Look up. Also keep in mind that RDL's and standard deadlifts are different enough, and the RDL's and stiff leg deadlifts generally don't let you lift quite as much.
I believe there are some links to some great technique videos in one of the lifting stickies. T-nation I think is the source.
Good luck getting through the injury!