Whats up with my dyno run?? Dip and lower numbers...

A while back I went and dynoed this as a baseline.



We then tried to burn a chip but my car wouldnt start with it so he said I needed to bring my car back and we will reformat it and try again. Well in between those periods I blew a HG. Fixed that and went back. I dynoed 329 as a baseline that time but wasnt too worried cause I thought I would get more then what I lost with the chip and some tuning. Next run I dynoed 367 which I was more then happy with. After somemore tuning it was back down to 324. Tuner said that the clutch was slipping and was giving me unreliable numbers. I dont have any of the second time graphs but I will post them when I get them but those graphs looked very similar with the dips and stuff. Could that be symptoms of a slipping clutch or a miss in my ignition? What else could cause that?