PR in reps for Deadlift

I'm definitely progressing on my deadlift.  2-3 months ago, my 1RM was 325, and I was barely able to get it up.  Yesterday I managed to pull off multiple sets, one for 3 reps and one for 2 reps.  I'm almost positive my back could have handled more weight.  My grip, however, could not.

That's been the theme since I started deadlifting.  My grip is shitty.  When doing 1 handed rows, I feel the weight just slipping through my fingers and I have to put the weight down for a half second in between each rep.  Same deal for shrugs and even sometimes weighted chin ups/pull ups. Maybe I need to get one of those hand grip things to squeeze while I'm driving to and from work.

Here are the sets.
2/6/12 - Monday
Deadlifts - 3 sets
135x8 (warmup)
225x5 (warmup)
325x3 PR
325x2
305x5

Chin ups - 3 sets
25lbs x5
25lbs x5
25lbs x4

Chinups goal is to get 10 straight reps with 25lbs hanging from my waist.  Then, on to 45lbs.